Speedo and Rev counter behaving oddly!!

I think I have an alien in my dashboard!! I have a fault with both my speedo and rev counter. I own an N reg disco 300tdi auto and recently both the speedo and rev counter have been behaving oddly. I can be driving along quite happily when my rev counter or speedo will suddenly drop to zero and then pick back up again to the correct reading. My rev counter also seems to do this during gear shifting. Is there a loose connection somewhere or do I really have an alien in my dashboard???

sounds like a bad connection somewhere, probably an earth as its affecting both

stands a chance of the printed circuit having a fault on it

Cheers going to have a good look at it this weekend.