This is not severe, but still annoys me every time that it comes up. Look at this screenshot:
Here I have the project set up so that ClickOnce will automatically increment the revision number after each publish. Well, something apparently is not working, because it seems that at least once a day, I get "Version already exists on the server" errors.
Blah! Is it me, or VS2005 that's at fault? I'm going to blame the latter, since I never make mistakes.