gcm-output of GCMUtility not playable in Dolphin?

[hjiuizjjhghh]

I used GCMUtility on Mario Kart to create a much smaller gcm file from it. The resulting gcm (I created it twice and checked the sha1-checksums to be sure there was no error on disk or RAM) crashes when trying to load a specific course in the game. Is this an issue in dolphin with GCM? (afaik the gcm should not change the game data but only replase padding)

Thanks