Re: Twinview Geforce 9500GT
as an update to this issue: I replaced the passive cooled GT9500 with an active cooled GT240 and voila , the problem is gone. It seems the temperatures had been the cause of the problem.
9500 GT ~ 58 - 65 Degree C versus 240 GT ~ 35 -45 Degree C
Personally I preferre a passive cooled card, but for the timebeing I can live with that