I'm not sure how thorough Visio's uninstall process is. It may leave some artifacts behind. I'm not going to go thru the process just to check this out. I believe Paul, yes, I'm speaking for him without permission, has experience with Visio and the registry.
Of course, you could unistall again, and see what's up. Your problem is unusual. Or, you might go into the registry, but, I'm not sure what to look for, perhaps Visio.exe. Perhaps you can see the command that is executed and then see if there's a "5" that looks somewhat suspicious. Sorry I can't be of more help. If you do make registry changes, back it up first. Paul should be back at a decent, European time.
Wapperdude