Problem with your dongle maybe?
Are you working with imported files? Usually I just get a crash. Rarely locks up.. but sometimes I get an error and then I get locked out of all the controls like I made it mad so the security stops working. Annoying.
I think 2.0 doesn't run on anything higher than windows 98 or so. what windows version are you using it with? that may be th problem
check fonts. empty your TMP folder. if you are importing an .ai file, make sure you use the correct one. omega has two imports for both .ai and .eps. pick the wrong one and....