I had to destroy and recreate the .wdproj file for the web site deployment project here at work in order to make it work with .NET 4.0. Unfortunately, it didn't get checked in, because Remote ClearCase didn't notice it was checked out (or hijacked) when I searched for changed files, apparently because there was a discordance.
When we realized that there was a discordance and I tried to check the file in, ClearCase managed to lose all of my changes.
So I built it again.
It didn't take that long, but it certainly was annoying.