$20 for the cause. 

I've been lurking here for a while and I would some other insight to this constant problem.

I have had this problem ever since the base game; I also have WA.  I will play for a while (an hour or two) and then the graphics will go blurry.  I can't read anything and everything is very blocky.  There will be times where I can have a long playing session, but then the same thing occurs.  My computer specs are as follows:

Windows XP SP3
Intel Core 2 Quad CPU Q800@2.33 GHz
3.25 GB of Ram
NVIDIA GeForce 9600 GSO

My computer was built in March of this year.  I had to roll back my drivers on my graphics card because the most current driver wouldn't allow the Sims 3 to start at all.  If I didn't search far enough in the forums, please let me know.  Thank you in advance.