Unpacked Files under XP SP1 doesn't work on SP2

[ivanov]

I found some cracks (unpacked files) that work on XP SP1, but not on SP2.
If this is due to Kernel changes, should be there any modification to the tool, e.g Olly, ImpRec or QuickUnpack?

And I have a program unpacked on SP1 and it works. I can load it successfully and see all program strings using Olly. Now I do the same under SP2, the unpacked result differs in size from the previous. Olly cannot load it due to error: "Don't know how to bypass command at...Try to change EIP or pass exception to program". I don't receive this error when loading the first unpacked file under SP1.

Any idea?