Well i undocked a ship while the ship was undocking and going on the takeoff rails i added some more takeoff rails when it undocked my ship got invisible and the accleration meter showed me infinite and the distance to the next sector showed me infinite too
It showed me infinite to the next sector and infinite on the speedometer but i was still on the same spot where i was before.
And after relog it was still the same:
EDIT: On the navigation panel it looks like this: