Delphi – System Error. Code: 8. Not enough storage is available to process this command

We have a few Win32 applications (coded in Delphi 2006) where sometimes the user gets an error message saying "System Error. Code: 8. Not enough storage is available to process this command.".

From the stacktrace it looks like it is always during CreateWnd call

Main ($1edc):
004146cc +070 app.exe SysUtils               RaiseLastOSError
00414655 +005 app.exe SysUtils               RaiseLastOSError
004ce44c +130 app.exe Controls               TWinControl.CreateWnd
00535a72 +022 app.exe cxControls             TcxControl.CreateWnd
004ce82a +016 app.exe Controls               TWinControl.CreateHandle
00553d21 +005 app.exe cxContainer            TcxContainer.CreateHandle
00586ef1 +005 app.exe cxEdit                 TcxCustomEdit.CreateHandle
005c331d +005 app.exe cxDropDownEdit         TcxCustomDropDownEdit.CreateHandle
004ceaf0 +074 app.exe Controls               TWinControl.UpdateShowing
004ceb1e +0a2 app.exe Controls               TWinControl.UpdateShowing
004cebdc +03c app.exe Controls               TWinControl.UpdateControlState
004d118a +026 app.exe Controls               TWinControl.CMVisibleChanged
004cb713 +2bb app.exe Controls               TControl.WndProc
004cf569 +499 app.exe Controls               TWinControl.WndProc
004b727d +4c1 app.exe Forms                  TCustomForm.WndProc
004cb3a0 +024 app.exe Controls               TControl.Perform
004c9f6a +026 app.exe Controls               TControl.SetVisible
004b6c46 +03a app.exe Forms                  TCustomForm.SetVisible
004baf1b +007 app.exe Forms                  TCustomForm.Show
004bb151 +14d app.exe Forms                  TCustomForm.ShowModal
007869c7 +0d3 app.exe UfrmPrice      770 +19 TfrmPrice.EditPrice
0078655d +009 app.exe UfrmPrice      628  +0 TfrmPrice.actNewBidExecute
00431ce7 +00f app.exe Classes                TBasicAction.Execute
004c2cb5 +031 app.exe ActnList               TContainedAction.Execute
004c397c +050 app.exe ActnList               TCustomAction.Execute
00431bb3 +013 app.exe Classes                TBasicActionLink.Execute
004af384 +090 app.exe Menus                  TMenuItem.Click
004b059f +013 app.exe Menus                  TMenu.DispatchCommand
004b16fe +082 app.exe Menus                  TPopupList.WndProc
004b164d +01d app.exe Menus                  TPopupList.MainWndProc
004329a8 +014 app.exe Classes                StdWndProc
7e4196b2 +00a USER32.dll                     DispatchMessageA
004bea60 +0fc app.exe Forms                  TApplication.ProcessMessage
004bea9a +00a app.exe Forms                  TApplication.HandleMessage
004becba +096 app.exe Forms                  TApplication.Run
008482c5 +215 app.exe AppName        129 +42 initialization

I've never been able to get to the bottom of what causes this and as it happens fairly seldom I haven't been to concerned, but I would like to find out what causes it and hopefully rectify it…

EDIT: Full Stacktrace

EDIT 2: More info… The client who experienced this today has had my app installed for about 4 months and it is running on his PC 8 hours a day. The problem only appeared today and kept reappearing even though he killed my app and restarted it. None of the other apps on his system behaved strangely. After a reboot the problem goes away completely. Does this point towards the heap shortage that Steve mentions?

EDIT 3: Interesting msdn blog post here and here on the topic of the desktop heap. Though I'm not sure whether this is the cause of the problem it certainly looks likely.