for nostalgia's sake, i wanted to flash 1.5 onto my 5.00 m33 psp phat and then update to 1.52 to feel what it was like when it was brand new. i select the 'install fresh 1.5 ofw' option in hellcat's recovery flasher. i have the 150 update eboot in root and the hellcat's starts dumping the files. however, near the end it gives two errors:

error while decrypting ipl_update.prx
error while decrypting SCE IPL

hellcat's continues and says done dumping files. if i try to flash this dump onto the nand using the 'restore backup' option, the psp bricks and i have to use pandora to get it back to 5.00 m33-6. any suggestions?