We have had some issues reported recently with our legacy VB6 application (running under Win7 64 bit) where certain forms that have been hidden are unloaded unexpectedly. When the application attempts to show the form again, the controls which we load dynamically (before showing the form the first time) are missing. The only way this can happen is if the form is unloaded, however the application does not call the unload method until the user exits the entire app - and yes, we do inspect the form's QueryUnload event to set cancel=True when the user clicks the Close button to HIDE the form.
This has only started happening recently, and certainly was not observed under Windows XP. Further, it doesn't happen under all Windows 7 installations, only some.
Does anyone have any ideas or has anyone else been having this problem?