blank screen after Tiger install


I upraded from Panther to Tiger and all of the installation worked fine. Startup was fine too...I logged in like normal and then I get a blank blue screen. No Menu Dock..nothing. I can move my mouse, keyboard volume controls work, eject button works, but no key commands work other than that. AND I also tried rebooting and running Disk Utility with the tiger dvd and holding down "c" right when I hear the chime on startup but....When I hold in "c" on startup with the DVD in, it's like it won't recognize just starts up and goes straight to the login screen anyway! Very frustrating problem. I also tried holding in the shift key and tried to login in safe mode but I still got a blank screen again loggin in that way. Is there any thing else I can do besides the "c" button thing or booting is safe mode? Cause it's not recognizing when I hold "c" on startup, and I'm still getting a blank screen when I login in safemode.

Thanks for any insight to this problem!

Dual 533 G4
OK so I tried one more thing....I re-started holding "option" and selected the other partition that still had Panther on it. After I ran Disk Permissions, repaired and verified everything tried to re-start on the new partition with Tiger on it, everything started fine and I logged in like normal but stil....blank blue screen!! Anyone else have suggestion??