Macbook Pro Core Duo froze and now boots into grey screen

Question

I was using my macbook pro (core duo) and just had a few apps open when it froze. I could still use my mouse but nothing else was working including force quit.
When I restarted my computer, it did the spinning wheel and apple screen and then went straight from that to a grey screen, to never come back again. Sometimes it flashes to black before entering the grey screen.
I did applejack and it finished with no errors...
I booted with the command option p and r.
I tried verbose and it gets past that and then gets stuck again at the grey screen.
Safemode boots and works fine (except my airport isn't detected) and probably some other things don't work.
I searched through other problems but couldn't find one that fit these specifications.
Any help would be graciously appreciated.

Answer 1

If safe boot works then it is probably a startupitem, launchagent, or launchdaemon that may be failing.  Look in your /Library/LaunchAgents, /Library/LaunchDaemons, and /Library/StartupItems.  All these are suppressed in a save boot.  You could start experimenting by removing all you see in those.  Or if you have some hunch of what may be a possible culprit delete that. Or one at a time.  Whatever.
When I say delete I mean just temporarily remove them.  Observe ownership and permissions when putting them back.
Note, I don't know why any of those items would suddenly start to fail just because you machine went south.  Perhaps some plist or other data got corrupted.