I often use keyboard shortcuts for action button options for speed (e.g. in forms and views Alt + 1 to trigger the first action button, Alt + 2 to trigger the second action button etc.). On a number of occasions when triggering action buttons in forms in this way, usually to edit a document (@Command([EditDocument])), I get an Error box, with the title PopulateTopMenus. There is no script running on the QueryModeChange or PostModeChange. I reproduced it intermittently on the R8 Personal Address Book as well.
Do others get this? Anyone have any idea why it occurs?