pc to psp to xbox trouble

so back when i was on 3.71 m33-2 on my phat psp i was able to transfer files from my pc to psp to xbox (modded and Old school) my psp was read as a FATx witch allowed me to do this transfer but after i upgrade to 5.00 m33-4 my xbox will now format it and the psp and pc can no longer read the momery stick. can any one help me get it back to a FATx and safely have my psp,pc, and xbox all friends agin. please. tips would be nice too:thumbup: oh and this means no more music movies apps and others anymore cause i still got the stock HHD:mad: Now i have to FTP every thing