Electronic Arts did a similar thing when creating the C&C First Decade collection DVD: Red Alert 2 was recompiled to modify CD checks (the game compares the CD

Electronic Arts did a similar thing when creating the C&C First Decade collection DVD: Red Alert 2 was recompiled to modify CD checks (the game compares the CD label against a hardcoded one, on top of the usual CD checks), but its expansion pack, Yuri's Revenge, was hex-edited instead to the same effect. This was done to maintain compatibility with the community-made patch that hooks into the EXE at assembly level to add new functions and fix bugs. (I'm the current lead developer for said patch.) See, EA is not all bad. :-)