clakor54, Sounds like incorrect color system to me, eg. koss system outputting pal or secam and possibly 50hz refresh rate as well instead of 60hz. Could also be related settings on the TV itself. The combination of issues points very strongly in this direction.
Holder350, Check and see if the system thinks the PS2 audio input is digital instead of analogue. I don't actually know this system but the symptom you discribe would be consistant with what i have written above in other systems. I assume you are using analogue connection because you say the connection direct to the TV works.
Simon.
I guarantee I'll tell you the truth and I guarantee I'll tell you what you need to know but I can't guarantee that I'll be telling you anything you want to hear.