The map in my head unit has gone intermittent. The head unit knows where I am at all times, so the GPS side is working but the map sometimes displays and sometimes won't. I have removed the head unit and the lower CD/Sat Nav unit and reseated all connectors and checked for loose wires etc, but nothing seems to fix it. I don't have the original map DVD to try reloading it. Any help would be appreciated.

Many Thanks.