Hi,
as some of you might remember I had the CTDs as well, but I am not using X-Enviro at all.
I was getting memory warnings from windows around 20 till 30 minutes before the CTDs every time. I thought, that the sim would just get slower due to that, but it seems the low memory was actually causing the CTDs in my case. I think so, because since I doubled virtual memory I did not experience any CTDs.
So what I think everyone with the CTDs should at least try, is to significantly increase virtual memory in windows.
Regards,
Chris