PSX/PSOne Fix for Custom Firmware 5.00 M33

Problems (0xFFFFFFFF) with PSX/PSOne games after installing custom firmware 5.00 M33? Dark_AleX with the quickness –

1. Download popcorn.prx (here)
2. Download a tool like PSP Filer or Xplora
3. Flash popcorn.prx to flash0:/kd using one of the above tools
4. Get down

- source: dark-alex