QUASI88 won't run games

I'm running the latest CFW on a fat PSP, with V0.6.3 of QUASI88 the PC88 emulator.

I unpacked it into the correct PSP/GAMES folder, and the emu loads normally. Then I select a variety of d88 game disk images which work on my PC (such as The Scheme, Popful Mail and so on), and then the system just hangs.

I've set the emulator to the correct V1/V2/N dipswitch, I've tried overclocking, and I even went and dropped the system roms (Kanji, PC88 BIOS rom and so on) which come bundled with PC emulators into the root folder.

Nothing. The games just do nothing. Just a blank screen.

I've seen Japanese sites with screens of the emulator running, so I know that it should work...

Any ideas?