Help: Flashing Finder


I encountered a very bizarre situation on my dual 2.0 G5 Mac last night running OS X 10.4.1. While I was reading an email (from a trusted was text only), all of my desktop icons disappeared and the Menu bar at the top of the screen kept disappearing and reappearing. In addition, the windows of any apps I had open were "flashing". Also, the little carrot at the bottom of the Finder icon in the Dock was doing the same thing....disappearing and reappearing.

I rebooted and my dekstop icons are still missing in action. I cannot launch any apps expect the ones located in the dock. I cannot access the applications folder to run any utilities to try any repairs.

Any ideas??

Please help!!!