LG usually is better than Samsung. It seems like you have Samsung.
I have 3 experiences w/ M1730 screens.
1 LG was great, 1 Samsung was horrible, and 1 Samsung was great, but not as good as the LG in colors (other than black...
What's the idle temp on it?
My cpu's idle @ high 50's (C) in hot summer apartment.
Haven't gaming lately, so I'm not sure how high it will go during games though.
If it keeps up, I would just call Dell, and ask for repairs.