i have this problem of which i have posted before. the weird thing is my philips itv digital set top box has a perfect picture thru rgb but my playstation2 thru rgb is way too dark and unwatchable. I have also tried a venturer dvd player which was also way too dark. I will have to try borrow some more items to check if they have the same problem.
I have a 28PW6006 and it works fine with RGB sources. Sky Digital looks really bright and sharp in RGB. Sorry to hear about your problems - I am very happy with my set at the moment.
My set has had two problems with it though unrelated to RGB - one was a very small geometry problem which I eventually solved via the service menu. The second was a sound interference problem which took Comet 4 weeks to fix. Now that both these things are fixed am very happy with the sound and picture quality (Saving Private Ryan on C5 the other night looked superb)