I have this same problem with Mappoint sometimes crashing when exiting. I have developed an applicaiton that uses VB .NET 2002 and the active x component of Mappoint to display a map.
I use the ActiveMap.Saved = true, AcitveMap.Application.quit and .closemap functions but I still get an error when the application closes.
I don't know of any mean to post a message to mappoint through the acitve x component to close out Mappoint.exe.
Is there other options with an active x component to get this to quit happening?