Dell and defective Nvidia GPU issue?

My Wife's Latitude D620 was purchased January 2007, in August of 2009 it started to show lines going across the screen when the system is cold.
Contacted Dell and they thought it was LCD so they sent me a new panel. I put in the new LCD and the problem continues. so they sent a tech the next day with a new MB. they put in a new MB and the problem has gone away.

So far after 5 months, problem has not come back. We got it with a 4 year warranty so we have about 1 year left on the warranty.

 

I had this defective chipset in another computer and the mobo failed 3 times over a span of 2 years. I'm totally paranoid about my Vostro now because it has the same exact chip. The GPU runs at around 60C degrees with normal use. When I ran RTHDRIBL it shot to 80C in 15 minutes.