I had the same thing once before the BC, when weather download was enabled. My altimeter and speed gauges gone too, also the inbuilt Shift+Z feature showed stupid values. I fastly turned off the autopilot and made a full visual emergency landing. Then I tried to reload the airplane, which did not help. Then I turned off the weather download and finally the situation calmed down. I took off again and entered that 45 minutes extra time to the PIREP. I do not remember though if it was accepted by the HC...I guess so.