I've been having this problem on occasions and when I reboot it usually clears up. It would be nice to find out what is causing it.Mike

I am hoping I may have solved the problem with that error message (in my case at least!)...Until now I have installed FSX on my other hard drives (ie not the C DRIVE). These are formatted in NTFS and appear to be compressed by default. Since installing its afresh on my C drive (which IS NOT compressed) I have had no nasty error messages!So I would helpfully suggest you try either unselecting "compression" on your other drives OR reinstall FSX on the OS drive (ie C DRIVE which is uncompressed).Hope this helps!Adam

Lets all pull our hair out and send it to the fsx development team.

Ewwwww. Hmm, although I can see it now Microsoft Hair Suite 2007. ;) If you don't activate your new Hair Suite within 30 days it jumps down off your head and kicks a kitten! :(

I have same problem and FSX is on a compressed partition. Looks like an avenue for exploration.The one thing I have found is that if I reboot a couple of times FSX comes good, very weird.I also found that I had lost all the lines on my CFG file up to the sound sub section. Replacing the missing lines didn't help the problem but as to why it should happen is a mystery.I'm off to do some uncompressing. Thanks for the clue.