Yes, I heard some people saying the quality of GBS8200 is random. By stable picture, what do you mean?
Mostly black screen, with the occasional blue flicker.
Using CVIDEO (pin #1) or CSYNC (pin #3)? I believe they are inverted signals.
Well, it looks exactly like the one you posted a picture of here).
I will find out more when I find me some cables.
Got SCART cables in the mail today, and ordered some DIN 45322 connectors on eBay. So in a (hopefully) short while I will be able to test my SCART to HDMI converter.
Unfortunately, the board has a quirk, you have to unsolder the cheap Elkos from the board and replace them with good ones, otherwise the picture always collapses.