AMD phenom on Gigabyte board w/Nvidia 9800 GeForce following the 8 step lifehacker article. Everything works great. I upgraded from 10.6 to 10.6.1 with no problem. If I update to anything more, 10.6.2, 10.6.3, 10.6.4 etc. with either the combo or regular update, around halfway through, the machine crashes and shuts down. No error in the Console log. I've tried in safe (chameleon) -x and -F and ignore cache. Always crashes the computer half way through the update.

What else can I try to get the updates installed without crashing?

did you get this figured out? if not, download the combo update from apple and everything you will need and put it on your desktop. boot it in safe mode (safe boot ...... -x boot flag) and install it. that should work.

Try boot with "-v cpus=1 maxmem=2048" and install AppleNForceATA.kext for supporting 64bits :'3