Won't boot past blue screen after software updates

Fixing up an old MacBook Pro (2,2) for my mom, here's what I did:

Wiped the drive clean and installed Snow Leopard on it, maxed the RAM at 3 GB and put in a new battery.

After I boot the machine and run software updates, it will not boot past the blue screen. Afterwards if I let the battery run all the way down and let it sit over night it will boot.

Here's the suggestions I've tried:

-Zapping the PRAM ect...

-Repairing the permissions and the disk itself

-Re-seating the RAM

-Putting the old RAM back in

-Safeboot, it will boot into safeboot

-fsck in single user mode

-Clean re-install of the OS

My questions would be the following:

-Has anyone seen this before?

-Is this a symptom of anything hardware specific (Drive failing, Motherboard ect...?)

-Anything I have missed?

Thanks a head of time.

UPDATE:

So replacing the drive did help in the fact that I now can get it to boot right away but only after re-setting the SMC. So I am unsure why the SMC needs to be re-set after each software update that I do, but otherwise it will not boot beyond the blue screen again. Any ideas?