Ryanair B737-800 loses flight display

I wonder what this is all about: A very brief report on the NTSB website states that a Ryanair B737-800 experienced a "partial, temporary loss of flight displays" after departure from Stansted just before noon on May 13, 2007. The reports says that the flight crew declared a PAN and returned to Stansted instead of continuing on to its destination, Stockholm.

The Air Accidents Investigation Branch in the United Kingdom is conducting the investigation.