Having the exact same problem, no matter which .exe file I launch from (shortcut or the original). Just started this evening--the other two times I launched the game, it worked perfectly fine, which leads me to suspect that it's tied into Telltale's site being down. (Which would mean the game phones home every time you start it up, rather than just the once?)
I'm on Vista 64-bit, for the record.
ETA: slader, out of curiosity, what was the graphical issue you were having with the voodoo effects? The last time I launched the game I had problems with it, too--one of the particle effects was a rather large, transparent square. I was going to boot the game up just now and see if that fixed the problem, but...er, well.