There is a thread on here referring to this prob, it involves lifting the top panel, and jamming something on the underside of the green multi plug that goes into the back of the display, I have done this several times without any lasting success, as you say it is annoying and if I have to continue "bashing" the top of the dash to revive it there is only going to be one winner, and I know who that is going to be. LOL
Clue the first letter is H and the last A
It can be found here.
Loss of display at top of dash
about 14 threads back. If you find a better solution please post it. I have now resorted to stroking the front of the display like we used to do with the early digital watches it seems to work as well, and does not bruise your hand as bad. LOL