CFW doesn't work on Fat TA-81 PSP

[malamutekid]

My friend accidentally updated his PSP to the latest official firmware after I modded his a few months ago, and now I cannot get cfw running on it properly. I've tried 3.71M33 and 3.81M33, and both of them freeze in XMB. I tried using iRShell's autoboot prx and that froze too. However, on official firmware it works fine (both 3.71 and 3.81). I've tried numerous magic memory stick solutions, and I still can't figure it out. When I did a nand dump it detected only 1 bad block. Any ideas?

[malamutekid]

i just disabled the m33 menu in m33 and now its not frozen! why would that happen?

[tomaversa]

idk why, but y didnt u ever try the latest custom firmware, 4.01m33....it would have a better chance on that one wouldnt it.