both the libUSBnull.so, and libPADwin.so do not work, or show up on the configuration screen. I've look threw the code, and everything seems in order, I think it's something to do on the emulators side, but the source code only comes in *.7z format, and I'm having a tough time getting it to decompress correctly.
for linux you gotta download a 7z extractor, in windows the newest winrar will extract it.
I still to this day dont see the point in using some wierd compression file type. Thers plenty of good standard ones like zip, rar, tar, gzip.
linuzappz solved the problem a while ago and sent me the correct version (in a thread in PCSX2 main forum) and src codes. Though this is not the one linuzappz sent me (because i was playing with GUI) it works fine i think. just rename it to PAD.tar.gz and copy pixmaps directory to PCSX2 main directory and/or your home directory.