hm.... it's quite possible that the chip dosn't support the formats then. it could be just one simply for allowing you to use imported versions, multi-region DVD player without the Action Replay, etc.

See if you can find out from your mate. If you remember what the chip looks like specifically you may be able to identify it simply by looking at the pictures online at the modchip website. Because some chips look quite unique to the others.

But if you could find out the specific chip you have, that would be a huge amount of help.