Hmmm... this is really strange. I removed all .NET Frameworks from my PC with Revo Uninstaller and cleaned up all registry entries, leftover files, etc. (I had 2.0, 3.0, 3.5 SP1 and 4.0), and donwloaded them again. But after a restart, 2.0, and 3.5 just couldn't install. Said it conflicts with previous installations. Anyway, Now I have .NET 3.0, and 4.0 now (I couldn't find 2.5), and OBMM doesn't work, naturally. Tomorrow, I'll try to reinstall all the Frameworks again, but now I gotta' go and have some sleep.