hitachi 43UWX10B Woes.

I have had a Hitachi 43UWX10B for a couple of years.For the most part the picture is excellent except for a problem that has me near suicidal. when the set has been on for five or six hours the set has a greenish fringing on the top of the screen. This is VERY visible during dark scenes. Sci-fi movies that are supposed to take place in outer space are almost unwatchable. The picture is perfect on bright scenes. My dealer set the convergence once but the problem persists. Any ideas as to what causes this and what to do about it would be greatly appreciated. Thanks.
Did setting the convergence help? If so, try pushing the auto-convergence button on the front panel. I sold the 43UW for 3 years and don't remember that happening to any sets. It might be electronic rather than mechanical. You might have to bring someone out again. Good luck Dan
Thanks Dlr, to answer your question no. It may have lessened it a bit but it seems to be getting worse. The Hitachi "magic focus" has no effect what so ever.The only advice Hitachi offered was to try another authorised repair service. Those places are relativly few and far here in Canada.perhaps I need to be more "assertive" with my dealer to get a good out come.
my dealer has ISF trained people on staff they Should know what is going on but...