Have a clean install of Win XP, fully updated and a clean install of the PS3 Media Player v 1.04 (Cant usse the later versions due to a bug in the menu only showing the root folder, not the files)
DIVX files work without a hitch, but I cannot play any MPEG-1 files AT ALL.
I know the files are fine as I used to use tversity (on another pc) which worked fine. (Switched cause tversity gave me the shits, had to restart it a million times a day to keep it working)
No other codecs etc installed, just as above. No tweaking of PS3 media player just as is.