afaik, Revirgin is a tool to rebuild the import functions of a SD protected file. but that's not the real problem in versions 2.60 and 2.70 (and 2.80 ?). cirkutz is right: the biggest problem there is the encryption of some small pieces of code (btw, that's why that vxd is installed !!).
and then there's another new feature: some "call" functions are encrypted (not the same as introduced in Safedisc 1.40.04 "R3", there the "call dword ptr" functions are messed up).
my source is reliable too
