Flashing gear display

Does anyone know what it means when the gear display is flashing while driving? I've seen before a couple of times that the gear display would go blank for a brief moment while shifting, but didn't worry much about it then since it shifted ok and the display came back within a second. But today one time it would continue flashing in 4th gear until I changed gear again. No warning lamps and the car seemed to shift ok, but I guess it must mean something?

 

This is a video of what it looks like: http://debian.as/~peter/flashing.mp4 . Am I really the first one to experience this? Seems to only be happening in 4th gear