Why does the Access 2000 runtime application that used to work on Vista doesn't now?

I wrote a database application in Access 2000 which worked fine on XP and earlier versions of Microsoft OS's. When I upgraded to Access 2003, I maintained the files for my application in Access 2000 format.

When Vista was released, changes needed to be made to my application: mainly all macros were converted to VBA routines and all visual basic function calls were prefixed by "VBA.". That seemed to resolve the incompatibilities that my application was having with Vista at that time.

However, my application will not run on a more recent version of Vista (Vista Home Premium). The startup form will appear. I can close the startup form, but the custom menu bar is corrupted. Two of the drop-down menus are missing items and show "Other..." instead. Whenever I click on a valid menu item, I get the "Execution of this application has stopped due to a run-time error" message.

I changed my application so I could by-pass the startup routine. I was hoping I could check the references. But what happens then is the application starts up; the custom menu bar and the built-in menu bar appear; and then, once again, the "Execution of this application has stopped due to a run-time error" message displays, and the application stops before the database window even appears.

Does anyone have any idea of what is happening here? Are these new problems because of changes in the newer versions of Vista? Or is there something more basic& something that I should have changed before?

Thanks.