The previous two threads I've read on this subject have yeilded three possibilities.
Codes are not supported on Pre-orders (maybe)
Codes are not supported on Games which contain "bonus" items (possibly)
and the most likely:
Codes do not work because Gamestop has not properly updated their database with pre-order games to categorize them as MMOs (Which apparently is what the codes only work with).
Edit:
It's for MMOs, not just MMORPGs. But I think that last case is probably the issue.
Edited, Apr 8th 2008 11:18pm by TirithRR
____________________________
Can't sleep, clown will eat me.