Hi wsmwsm
Not sure if you have dual core processors or not, but if you do, this may help.
this is from the Over Flanders Fields Forum, it was found that multicore processors could cuase issues. (mostly graphical stutters with timing issues between the various cores) but some have reported back that the game hanging or dropping back to desktop after short periods of flight had been resolved by appyling the single core affinity fix.
see link below.
http://combatace.com/topic/37997-changing-cpu-affinity-settings-manually-for-cfs3off/
Would also pay to mention your problem in the general discussion forum over trhere as well, this has been spoken about a few times in the past.
HTH's
regards Rob.
Thanks. I will look into this and post at the OFF site. The problem, of course, effects OFF/BHAH as well.
The darndest thing is that it will work for short periods of time . . . and quite well. Then after starting again, CTD often within seconds of getting to the UI.