diff --git a/frontend/apps/reader/modules/readerdictionary.lua b/frontend/apps/reader/modules/readerdictionary.lua
index f78f2c508..802c4b2c5 100644
--- a/frontend/apps/reader/modules/readerdictionary.lua
+++ b/frontend/apps/reader/modules/readerdictionary.lua
@@ -996,7 +996,7 @@ function ReaderDictionary:showDict(word, results, boxes, link)
         if not results.lookup_cancelled and self._lookup_start_time
             and (time.now() - self._lookup_start_time) > self.quick_dismiss_before_delay then
             -- If the search took more than a few seconds to be done, discard
-            -- queued and coming up input events to avoid a voluntary dismissal
+            -- queued and upcoming input events to avoid a voluntary dismissal
             -- (because the user felt the result would not come) to kill the
             -- result that finally came and is about to be displayed
             Input:inhibitInputUntil(true)
diff --git a/frontend/device/wakeupmgr.lua b/frontend/device/wakeupmgr.lua
index 46dc43c6a..724864cdb 100644
--- a/frontend/device/wakeupmgr.lua
+++ b/frontend/device/wakeupmgr.lua
@@ -88,7 +88,7 @@ with anonymous functions.
 @treturn bool (true if one or more tasks were removed; false otherwise; nil if the task queue is empty).
 --]]
 function WakeupMgr:removeTasks(epoch, callback)
-    if #self._task_queue < 1 then return end
+    if #self._task_queue == 0 then return end
 
     local removed = false
     local reschedule = false
@@ -147,7 +147,7 @@ If necessary, the next upcoming task (if any) is scheduled on exit.
 @treturn bool (true if we were truly woken up by the scheduled wakeup; false otherwise; nil if there weren't any tasks scheduled).
 --]]
 function WakeupMgr:wakeupAction(proximity)
-    if #self._task_queue > 0 then
+    if self._task_queue[1] then
         local task = self._task_queue[1]
         if self:validateWakeupAlarmByProximity(task.epoch, proximity) then
             task.callback()
diff --git a/frontend/ui/uimanager.lua b/frontend/ui/uimanager.lua
index 6ff885981..7f911cefb 100644
--- a/frontend/ui/uimanager.lua
+++ b/frontend/ui/uimanager.lua
@@ -521,13 +521,13 @@ function UIManager:close(widget, refreshtype, refreshregion, refreshdither)
     end
 end
 
--- schedule an execution task, task queue is in ascendant order
+-- Schedule an execution task; task queue is in ascending order
 function UIManager:schedule(sched_time, action, ...)
     local p, s, e = 1, 1, #self._task_queue
     if e ~= 0 then
-        -- do a binary insert
+        -- Do a binary insert.
         repeat
-            p = math.floor((e + s) / 2) -- Not necessary to use (s + (e -s) / 2) here!
+            p = bit.rshift(e + s, 1) -- Not necessary to use (s + (e -s) / 2) here!
             local p_time = self._task_queue[p].time
             if sched_time > p_time then
                 if s == e then
@@ -544,12 +544,13 @@ function UIManager:schedule(sched_time, action, ...)
                 end
                 e = p
             else
-                -- for fairness, it's better to make p+1 is strictly less than
-                -- p might want to revisit here in the future
+                -- For fairness, it's better to make sure p+1 is strictly less than p.
+                -- Might want to revisit that in the future.
                 break
             end
         until e < s
     end
+
     table.insert(self._task_queue, p, {
         time = sched_time,
         action = action,
@@ -602,6 +603,9 @@ Useful to run UI callbacks ASAP without skipping repaints.
 
 @func action reference to the task to be scheduled (may be anonymous)
 @param ... optional arguments passed to action
+
+@return A reference to the initial nextTick wrapper function,
+necessary if the caller wants to unschedule action *before* it actually gets inserted in the task queue by nextTick.
 @see nextTick
 ]]
 function UIManager:tickAfterNext(action, ...)
@@ -609,7 +613,14 @@ function UIManager:tickAfterNext(action, ...)
     -- c.f., http://lua-users.org/wiki/VarargTheSecondClassCitizen
     local n = select('#', ...)
     local va = {...}
-    return self:nextTick(function() self:nextTick(action, unpack(va, 1, n)) end)
+    -- We need to keep a reference to this anonymous function, as it is *NOT* quite `action` yet,
+    -- and the caller might want to unschedule it early...
+    local action_wrapper = function()
+        self:nextTick(action, unpack(va, 1, n))
+    end
+    self:nextTick(action_wrapper)
+
+    return action_wrapper
 end
 --[[
 -- NOTE: This appears to work *nearly* just as well, but does sometimes go too fast (might depend on kernel HZ & NO_HZ settings?)
@@ -1142,7 +1153,7 @@ end
 --]]
 
 function UIManager:getNextTaskTime()
-    if #self._task_queue > 0 then
+    if self._task_queue[1] then
         return self._task_queue[1].time - time:now()
     else
         return nil
@@ -1153,25 +1164,21 @@ function UIManager:_checkTasks()
     self._now = time.now()
     local wait_until = nil
 
-    -- task.action may schedule other events
+    -- Tasks due for execution might themselves schedule more tasks (that might also be immediately due for execution ;)).
+    -- Flipping this switch ensures we'll consume all such tasks *before* yielding to input polling.
     self._task_queue_dirty = false
-    while true do
-        if #self._task_queue == 0 then
-            -- Nothing to do!
-            break
-        end
-        local next_task = self._task_queue[1]
-        local task_time = next_task.time or 0
+    while self._task_queue[1] do
+        local task_time = self._task_queue[1].time
         if task_time <= self._now then
-            -- remove from table
+            -- Pop the upcoming task, as it is due for execution...
             local task = table.remove(self._task_queue, 1)
-            -- task is pending to be executed right now. do it.
-            -- NOTE: be careful that task.action() might modify
-            -- _task_queue here. So need to avoid race condition
+            -- ...so do it now.
+            -- NOTE: Said task's action might modify _task_queue.
+            --       To avoid race conditions and catch new upcoming tasks during this call,
+            --       we repeatedly check the head of the queue (c.f., #1758).
             task.action(unpack(task.args, 1, task.argc))
         else
-            -- queue is sorted in ascendant order, safe to assume all items
-            -- are future tasks for now
+            -- As the queue is sorted in ascending order, it's safe to assume all items are currently future tasks.
             wait_until = task_time
             break
         end
diff --git a/frontend/ui/widget/confirmbox.lua b/frontend/ui/widget/confirmbox.lua
index 181769420..fd892031a 100644
--- a/frontend/ui/widget/confirmbox.lua
+++ b/frontend/ui/widget/confirmbox.lua
@@ -186,7 +186,7 @@ function ConfirmBox:onShow()
         return "ui", self[1][1].dimen
     end)
     if self.flush_events_on_show then
-        -- Discard queued and coming up input events to avoid accidental dismissal
+        -- Discard queued and upcoming input events to avoid accidental dismissal
         Input:inhibitInputUntil(true)
     end
 end
diff --git a/frontend/ui/widget/infomessage.lua b/frontend/ui/widget/infomessage.lua
index 2edddf552..5c5888a78 100644
--- a/frontend/ui/widget/infomessage.lua
+++ b/frontend/ui/widget/infomessage.lua
@@ -234,7 +234,7 @@ function InfoMessage:onShow()
         return "ui", self[1][1].dimen
     end)
     if self.flush_events_on_show then
-        -- Discard queued and coming up input events to avoid accidental dismissal
+        -- Discard queued and upcoming input events to avoid accidental dismissal
         Input:inhibitInputUntil(true)
     end
     -- schedule us to close ourself if timeout provided
diff --git a/plugins/autosuspend.koplugin/main.lua b/plugins/autosuspend.koplugin/main.lua
index 3fd551f4f..db868019d 100644
--- a/plugins/autosuspend.koplugin/main.lua
+++ b/plugins/autosuspend.koplugin/main.lua
@@ -33,11 +33,12 @@ local AutoSuspend = WidgetContainer:new{
     auto_suspend_timeout_seconds = default_auto_suspend_timeout_seconds,
     auto_standby_timeout_seconds = default_auto_standby_timeout_seconds,
     last_action_time = 0,
-    is_standby_scheduled = false,
+    is_standby_scheduled = nil,
     task = nil,
     standby_task = nil,
     leave_standby_task = nil,
-    going_to_suspend = false,
+    wrapped_leave_standby_task = nil,
+    going_to_suspend = nil,
 }
 
 function AutoSuspend:_enabledStandby()
@@ -135,6 +136,10 @@ function AutoSuspend:init()
 
     if Device:isPocketBook() and not Device:canSuspend() then return end
 
+    -- We only want those to exist as *instance* members
+    self.is_standby_scheduled = false
+    self.going_to_suspend = false
+
     UIManager.event_hook:registerWidget("InputEvent", self)
     -- We need an instance-specific function reference to schedule, because in some rare cases,
     -- we may instantiate a new plugin instance *before* tearing down the old one.
@@ -199,7 +204,14 @@ function AutoSuspend:_unschedule_standby()
     end
 
     -- Make sure we don't trigger a ghost LeaveStandby event...
+    if self.wrapped_leave_standby_task then
+        logger.dbg("AutoSuspend: unschedule leave standby task wrapper")
+        UIManager:unschedule(self.wrapped_leave_standby_task)
+        self.wrapped_leave_standby_task = nil
+    end
+
     if self.leave_standby_task then
+        logger.dbg("AutoSuspend: unschedule leave standby task")
         UIManager:unschedule(self.leave_standby_task)
     end
 end
@@ -326,6 +338,8 @@ end
 
 function AutoSuspend:onLeaveStandby()
     logger.dbg("AutoSuspend: onLeaveStandby")
+    -- If the Event got through, tickAfterNext did its thing, clear the reference to the initial nextTick wrapper...
+    self.wrapped_leave_standby_task = nil
     -- Unschedule suspend and shutdown, as the realtime clock has ticked
     self:_unschedule()
     -- Reschedule suspend and shutdown (we'll recompute the delay based on the last user input, *not* the current time).
@@ -587,7 +601,7 @@ function AutoSuspend:AllowStandbyHandler()
         -- (in case we were woken up by user input, as opposed to an rtc wake alarm)!
         -- (This ensures we'll use an up to date last_action_time, and that it only ever gets updated from *user* input).
         -- NOTE: UIManager consumes scheduled tasks before input events, which is why we can't use nextTick.
-        UIManager:tickAfterNext(self.leave_standby_task)
+        self.wrapped_leave_standby_task = UIManager:tickAfterNext(self.leave_standby_task)
     end
 end