firmwares

hi everyone might be stupid question but i downgraded my 2.71fw psp yesterday to 1.50 sucessfully then installed n64 emu with a couple of games ok all worked fine, then installed dark alex 3.30 oe-a firmware thinking it would all work together but it dosnt what can i do to get n64 working again? thanks

i also seem to have 2 corrupt files in the games part of the mem stick and 1 corrupt file in photo part??

thanks might be stupid but how can i switch back to the 3.02 firmware to run newer umds?

[ace]

Yep it is, you don't need to downgrade to a lower firmware to play newer umds....3.30OE can play any UMD (correct me if im wrong). Downgrading to a sony firmware from a custom firmware to play newer UMD's is just pointless :p