Jelle Druyts

Your dll's are cached in a few places: you have the GAC's Download Cache if you use downloaded assemblies (that cache can be cleared by running "gacutil /cdl"), the Visual Studio WebCache (can be cleared by closing all instances of Visual Studio and deleting the VSWebCache folder in your windows user profile) and even the Internet Explorer cache (can be cleared by deleting the cache files in the Options screen). If something goes wrong in any of these places (and trust me, it does sometimes), you could be working with a wrong version of your code and you may spend hours looking for a bug you already solved. So when in doubt, delete the caches!