The only encoder I was ever able to get a stable connection with was over composite/s-video and HDMI using a cheap encoder. Component from JROK and Neobitz both were iffy.
I have my PGM working with a supergun using neobitz encoder with component video. Works fine, but I have to use a sync cleaner to get the best picture.
Depends on which revision PGM. There were 3 iirc. Most common was the wacky sync one. The last revision worked by far the best. I wish I could find my notes on how to find them.