Don't quite know what to make of that. Especially since it crosses over the Dashboard. Have you reset PRAM and the usual resets to the computer? The other one is to shutdown, disconnect power and pull the battery and hold the power switch for a count of 5 (Cannot Remembe off the top of my head). You also might want to run the Hardware Diags off The #1 Install Disk and see if it could provide some clues.
Bill......