Nevermind, it's set, but I have a new problem.
Despite seemingly converting correctly, Mega Man X3 (E) read as a corrupt file and failed to run. Did I just download a bad ISO?
Try transfering it again or try downloading another ISO.
Is your PSP hacked? It won't run unless you sign it (If it's under 700 and some MB) or if it's jailbroken.
I'd wager a guess that it's related to the inputted SLUS number. Each game has a special one, some games need that altered to work correctly (Resident Evil, among others).
GameID again won't break anything other than compatibility. You won't experience a corrupt message if it's wrong, you'd more likely encounter a freeze at some point once the game has loaded.
You're obviously doing something wrong in the conversion process. Be it a poor initial image, a poor conversion tool or simply placed in the wrong location with a folder name which is too long.
Change the name of the folder containing the eboot to mega. Any change in error?
Use popsloader to start the game with 3.52 pops. It's possible you're just getting poorly ripped images.....If your images are bad then the best option is to ebay the game and rip yourself. Have you tried the original PSX iso's in pSX or ePSXe to see how it performs?