IL-2 crashes in full mission builder 4.09

[workky]

I got a problem with 4.09.This is just the stock game,no mods or anything .It will crash in full mission builder if i am running in perfect mode.It is fine until you put an object down.When you start giving it waypoints the FPS drop to about 5fps,and after a few secs there it will crash.If i run it in excellent,it runs fine with no problems.I really dont recall when this problem started,ive tried changing drivers.This did not seem to help at all.
Any help would greatly be appreciated,Thanks
im running 9.10 Cats
4870 1 gig card
4 gigs ram
6850 dual core CPU
Abit IP35Pro
2 western digital raptors in raid 0
Windows7 64 bit ultimate
thermaltake tough power 1200watt power supply
Creative XFI sound card