crashing games

[grass_is_green]

Hey everyone,

I have a problem with my xbox I recently got it modded it with the xecutor chip, and most games I back up into the harddrive work fine but some games keep crashing. For instance fifa 2004 - it goes to the fifa 2004 screen and just freezes, starwars KotOR crashes if it enters a load screen, and mame doesn't even work. These games all worked fine before then one day they just stopped working.
Any help will be appreciated. Thanks.