Restart Problems Every Other Time!

Ok I've searched and searched and can't seem to find the answer to this. I've called AppleCare and they tell me to clean out the startup items for the user I'm having problems with. I've done all this and still have the same problem. Every other time my Mac Pro is restarted everything freezes when it starts.

I thought at first that it was just something random and kept restarting to resolve the issue, but I figured out that it does it exactly every other time. I can't seem to figure out what is causing it.

I installed some memory when I got my Mac, but I've already removed it and tried to see if that fixed it, that didn't work. Everything is upgraded 100% and I've ran all the Onyx scripts to make sure all the permissions are set correctly and so on. Still not working. Does anyone have any other ideas?

Send it in if it has AppleCare coverage. Sounds stupid, but you've done a lot already and now it's time Apple fixes this for you.

I would have already done that, but I need the computer for work and school. Can't go with out it longer than an hour or so.

As a last ditch effort, try creating a new userid and using that - this will eliminate anything related to your current userid.

Also, check your Macintosh HD->System->Library->StartupItems, just to be sure that you know what is there and it makes sense to you. Could it be one of these?

There are actually quite a few things in that folder. How can I safely figure out what isn't needed and what is?