thanks for your reply. actually i could continue at the next patrol, so it's not so bad; only i lost the medals/promotions etc. a bit annoying but not so bad. your loosing the entire carrer is awful!
what i do now (if it's any help for you) is save (away from ships, surfaced, etc). sooner or later, you have to quit the program. when you load that mission, if it works (ie. if it doesn't crash), i save that as "savegame... - cp" i add the "-cp". now i can exit the game and backup my carrer because i have just found out that i can load the "-cp" savegame and can start from there.
got it?? i'm not sure i explained it very clearly
hope it's of some help. cu!