I wanted to make an account just so I could thank you for this thread. From following the instructions, I actually got it working on an 800 MHz G4 with 512 MBs of RAM. I imagine it would work terribly for HD files, but I only ever use PMS to stream lo-fi AVI files, because if I have an MKV, I'd rather just convert it to MP4 with Quicktime Pro and stick it on a flash drive, rather than relying on my network connection.
Anyway, thank you for this. I never would've figured this stuff out.