Each and every time I've compiled my solution over the last month, I've had to wait approximately 30 seconds for the IDE to resume after compiling. It simply said Build failed / Build succeeded and would not let me click anywhere in the UI for a painful half-minute (which I put to good use).
At first, I assumed this was another "feature" of VS.NET that was causing me pain and suffering, just like when my VS.NET 2005 decided to make me pay for cheating on it with another IDE (Eclipse) when I was working on a few open source Java projects using Eclipse (StatSVN and jUCMNav).
I decided to launch VS.NET 2008 in Safe Mode to verify if this would fix my problem and, to my surprise, it did. I probably have an evil add-in that was migrated from VS.NET 2005... to be investigated.
Update: Even in safe mode, it started doing it again after a couple hours of work. I'll file this into the "unexplained" category, alongside my mysterious "clipboard doesn't work for large images when memory usage is too high". From what I can see, Windows 32bit with the /PAE or /3GB options simply doesn't work. I need to upgrade to a 64bit OS to use my 4GB ram because the startup options aren't working well for me.