GTA 3 & C&C Generals

[Minesweeper]

Even though both games have exactly the same copy protections on them (SD 2), I encountered major problems when trying to create an image of C&C Generals using VirtualDrive. GTA 3 on the other hand took less than 30 mins to image (and it worked) as opposed to the 3 hours it took for C&C (whose final image was corrupted).

VirtualDrive is a prog that lets you create up to 23 "virtual" cd drives which images of cds can be loaded onto.

Could anyone explain why this is the case?

Thanks.