When trying to jump when the server is *overloaded* (the red message about server being overloaded comes about every 5 minutes or so), 2/3 times the ship doesn't move, but it still consumes the 'jump' charge.
Reproduce :
Get inside a ship with jump drive and load it Set as waypoint to anywhere (Try to)Jump Nothing happens but the jump drive charge is consumed (if it DOES work, make sure there are a lot (20+) of people on the server, and repeat 2 or 3 times).
I'm on the GameHopper server 213.136.69.160:4242 There, this will happen to me about 2/3 of the time, so multiple times per game hour. I just lost 2 ships because of this today (could not escape from pirates with unarmed ship), and so decided it was time to report this issue.