taltamir,
I, too have experienced the "debugger detected" error. In my case, I did not have a previously-installed demo to deal with--just a fresh install of the full game--so demo "remnants" definitely weren't the cause. It may be a Vista thing. When I installed the program on WinXP, everything workerd fine, but on Vista, nope. I changed the compatibility settings on the program to WinXP, but that didn't help. I tried emailing cinemax support a week ago, but I've heard nothing from them yet.
Just thought you should know that you're not alone with this problem. I'm still searching for a solution on this one...