Cannot Login to Admin Acct.

I can't login to my admin account.
I have two account on startup. Mine and a guest account. I have no problem opening the guest account, but when i enter my password into my main account, it accepts it, and proceeds to a blue screen, like the background, and then bounces back to the login screen.

Any ideas??

Have you done Verify Disk from Disk Utilities? It solves common problems.