Man, I was at this for hours, trying to figure out what I was doing wrong.
I couldnt find the answer anywhere, until I looked at MAWS more carefully.
The rom needed is svcpcba (this is set 2), however you also need five files from the svcpcb rom:
Add these five files to your svcpcba zip then convert them into the cache with the converter (romcnv)
copy that folder to your memstick aswell as the zipped rom and there you go....working...allthough a lil slow and no sound.