loading another copy of an assembly on Reflector might cause little headaches

First of all, if you haven't used Reflector, go download it now and start looking around in the BCL assemblies to see how things are really done behind the scenes, it can decompile code to IL, C#, VB.NET, Delphi, Chrome and MC++, I can't really say much about the quality of the Delphi and Chrome versions of the code it generates, but the C# is pretty good

anyway...
one thing to be aware when using reflector is, if you have an assembly loaded, and you try to load a different copy of the assembly in a different directory, it won't load it, it will keep the previous assembly loaded, and if you were loading it to see if there was a mismatch you'll think they're equal

what you have to do is just to right click on the assembly you're trying to reload, select close, then open the other copy and you're good to go