Problems after RAM upgrade/install

This is the first time trouble-shooting my Mac since I purchased it in 2005. About 3 weeks ago, I replaced the stock 512MB RAM with 2x1GB. I know of the specifications (DDR SDRAM) and the replacement is supposed to be compatible. But, as my post would indicate, something's not right.

Problems include overheating, OSX sudden shut-down (something to do with unresolved kernels), erratic program behavior, spinny wheel of death, and many other issues. The computer is running slower than before, and, with many digital projects due in a week, I'm afraid it's going to die.

I'm a 21 year old student who professes to know very little about Macs, so any help is appreciated!

Firstly try running it off just one 1 gig stick. Then try running it with the other 1 gig stick. See if you can isolate if one or both modules are causing the problem

Thanks!

I was able to remove one of the chips successfully and now it seems to be running fine. It's getting recognized and some of the immediate problems (like not waking up from sleep) and overheating are (so far) eliminated.

If I do encounter any more problems, I'll switch out the other chip. And if all else fails, I'll just put the old chip in.

Again, thanks for the advice.