Dash problems

The last few weeks I've been having some trouble with the dash gauges and lights. Several times, all my instruments acted completely dead except for the Speedo and Alt. It happened when I would first start up the car, then would last 15-20 minutes, after which everything went back to normal. Then last night, my gauges all worked, but I have no dash lights--these did not come back on. Does this sound like one of those problems with the dashboard voltage limiter, or do you think I've got a more serious problem?