nitty - perhaps the adjustment pots are bad/not working. I'm not an expert but I don't think it's a cap kit type problem. Outside of the screen adjustment, the picture looks ok to me. If there was fold over, jail bars, or some other type of graphical problem, then it's probably caps.
I actually have something for the thread
I've been casually looking for a replacement/backup DK board. My board works ok but I'm starting to get some girder splitting in the lower right. Not a huge deal but it drive me nuts sometimes. I also occasionally get this >
http://www.hitbox.tv/video/286389 . Seems to occur when I strongly move left or right...or in this case quickly moving left/right to try to get the fireboxes down the ladder. Seems board related, right?
Thinking it's time to start aggressively looking for a new board. There are a bunch on the bay right now for $180. I can probably keep waiting and hope to score one in the 150-160 range but for DK, I'm ok spending the extra $$.