Atakacs,
I've had this situation occur with loss of GPS, specifically over White Sands New Mexico, USA. We were out of GPS signal for 200 miles. Fortunately only adjustment was to inform ATC, maintain a heading mode, and back up with VOR, if one happens to be along route.
Super pilot: Automatic realignment does occur, and return to NAV mode was uneventful. No flight control abnormality in this specific example.
Safe journies...Sushi