If this is an anti-piracy measure, I can guarantee that I have purchased a key through the MuLab site, and received my key from them through my email.
The only things I can think of is that I tried to use an incompatible VST plugin (I run 64 bit and the plugin was 32 bit), my key doesn't support VST plugins, or that I used the same key twice on the same machine so that I could run that 32-bit VST plugin in a 32 bit version of MuLab. If this is an anti piracy measure because of the duplicated key use, I did not know that this would happen. I did read through the EULA and I didn't see anything explicitly against using the two versions on the same machine, but I could be wrong.
