Hi Mark,
There are alot of user out there who have the same problem with Payware planes running on FSX.  The default planes work fine.
Here's one solution that I'm a little hesitant to try but really want to resolve this. Check it out and let me know if you have any thoughts. I'm running Windows 7 64bit.
http://answers.microsoft.com/en-us/windows/forum/windows_7-gaming/win-7-64-bit-fsx-fatal-error-ctd-restart/14fc20fa-9dca-465b-be42-146414087ec5