Odd one - flickering RPM and speedometer guage when unlocking car

[b206]

As the title says when I unlock and open a door the RPM and speedometer gauge flicker quickly (about 10mm back and forth) - sounds like a machine gun (not as loud though :p ).
This is intermittent - happened again today so thought I would post on here to see if anyone knows what it could be ?

Everything else on the dash works fine - just this odd issue.

Cheers.

[b206]

This has started getting worse, no longer intermittent! - almost every time I unlock the car it does it. I've uploaded a video:


http://youtu.be/_OuoO2Wi4LQ

If I don't lock the car it's fine - sometimes it will reset relatively quickly (as above), sometimes I can drive several miles until it resets.

Clock no longer keeps time either - could be related ?