I hate to say it but I have also been struck by the *** Kraken. Several days ago KSP .23.0 crashed. I rebooted and my active flight missions except for flags disappeared. I had 2 of my orange suiters on continuing ground duty in rovers near the flight center so that they didn't come pop into any new vehicles. I also had 3-4 docked kerbals in flight on a station at a 150km and several inter planetary probes flying. All of these were vanished from the flight center completely. All of the crew were listed as MIA. I shut KSP down again and restarted and all the crew returned to active status however the missions were still gone. The quicksave is also missing however I accidentally hit it before shutting things down.