It's quite unlikely that something between the computer and PSP caused this error. It's more likely that you don't have the right homebrew kernel installed or something related to that. Many homebrew applications require that you install the 1.5 addons for whichever kernel you're running so if you don't have that installed then I would recommend it. Other times I've found that the applications will boot from the GAME150 folder but not from the GAME folder or vice versa. Also, if the emulator you're using came with two folders (Emulatorname and %Emulatorname%, eg.) then make sure you put both folders on your memory stick. What version of custom firmware are you using?