Ok, I found the problem... well, I found it a long while ago.
I took your advice on using a house fan. I placed it behind the IO, and turned the oscillation off.
WOW... the temp of Q16 went from a max of 80°C down to about 50°C. This was with the RAM door off, but after putting it back on, the temp didn't rise too much. My crashes have stopped.
My conclusion is that just a little bit of air flowing thru the IO case will cool it quite a bit. Q16 is in a spot where it doesn't seem that it would get much of a draft without any help.
A cheapo fan in a strategic spot would help out a lot. I'm not about to do this, so I'm going to experiment with a heat sink for it.
Here is what I picked up at my local radio hack:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F005%5F007%5F004%5F000&product%5Fid=276%2D1368
It looked a bit large, but out of the only two they had in stock, this looked to be the best bet. If you place it so that the fins are vertical, it will fit right in. The problem is fastening it down.
I found out that with the RF shield on, it fit incredibly snug. Now, the painted parts of the aluminum heat sink do not conduct electricity. However, the ends of it that are not painted do. I don't think this will be a problem in shorting anything out.
I plan on just fastening it to the RF shield so that when I put it on, it's in the right place everytime.
I plan on doing this tomorrow, and I'll post my results.
SnackPack