messiah 2 probs

[murdie]

hi all,
wonder if anyone can help with my m8s ps2, hes just had a messiah 2 installed in his v7, seems to work fine ,boots really quick but randomly locks up on backups of vice city and tiger woods 2003.
Its not the games coz i have tried them with no probs, the originals work fine and so do cdr backups.
basically wot i need to know is - is it likely to be the chip(so i can return it) or some other problem.
cheers for any feedback
murdie