I keep running into problems where I can no longer quick save, recover my vessel or return to the space centre. The only way to quit out of the current ship is to reload the last quicksave or kill the game. I'm currently landed on Kerbin with a plane, in the middle of a set of seismic missions. Starting the game from fresh, I can switch to flying the plane, and if I hit F5 then quicksave works. If I start moving, such as to turn the plane around, then at some point quick save and other operations cease functioning. Sometimes I can do something, come to a stop, and perform a quicksave. Most of the time it fails. I can change to map view (and set a navigation target for the next location), but I can't switch to any other active craft, I can't recover my vessel, and I can't return to the space centre (I get up the menu, but if I select 'Space Center' nothing happens). This is a campaign mode game I've been running since 1.0 came out (though I haven't played it for about a month). Any ideas? Thanks.