296 keeps shutting off

Today, I was IFR over the fog near LIN VOR and thought I'd use the 296
to give me the AWOS freq at Jackson airport. So I moved my pointer over
to Jackson and hit enter and the 296 shut off! So I hit the power
button and acknowledged the first screen as usual, move the pointer
over to Jackson, selected enter and it did it again! So I again powered
it up (hit the power button, looked at the Cessna picture, hit enter to
ack. its a VFR unit). This time, I simply hit "page" to give me a good
map view and it shut off again!!
So I powered it up again and it seemed to work fine. Just to test the
battery, I unpluged the unit power from the cig lighter and it popped
up the normal 30 second window, "do you want to run on battery". So,
the battery seems fine, and the unit didn't act like it lost power.

Has anyone else seen this? Is there some sort of firmware upgrade I may
need?

-Robert