when i put Twisted metal 4 on my psp, it says corrupt. WHY?

i also tried this with Castlevania:Symphony of the Night , and when i put the eboot.pbp and keys.bin file on my psp in the folder(name of game) in the PSP/GAME area, i look on my psp and its corrupt, WHY? this happened with Castlevania:Symphony of the Night also, why, why,why?

can anyone help me out, im using psp firmware 3.90 m33-2 and when i convert the EBOOT.PBP file(and KEYS.BIN file) from the .IMG file i put the 2 (eboot and keys) into my PSP/GAME folder on my memory stick and when i go to look at it, it is corrupt, this happened with Castlevania:SoTN and Twisted Metal 4. So please help me. I KNOW BOTH of the games are not corrupt.

hae you tried formatting your memory stick and putting them back on?Also refrain from double posting in the future.

its fine now. Sorry for the double post