Indeed it is. I noticed that all the RAM slots were occupied but only 512MB was recognized. Further inspection showed that the 2nd pair of RAM are 1GB but not visible. I reinstalled the big sticks in the 1st pair and known RAM in the 2nd pair. Still no go for the 2nd pair.

I'm guessing it has something to do with the amount of dust inside might have done something. I will try a PRAM reset as well...maybe that will work.