Thank you also for the other reply about add ons.    When I thought about it further I realized an add on conflict being the problem unlikely as there are two totally different configurations for FS2004 and FSX.    The above reply seems to confirm this is not the issue.

 The tip (request) about other audio devices rings a faint bell.    Long time ago I installed a virtual device drive for real-time audio sampling.   Perhaps this is still active and causing a problem!    I will look into it further and let you know what I find.   Thank you very much for all the input and suggestions.

 My thanks for the control panel / device driver tip - that was the key.    I had installed a real-time audio monitor long ago.   It appeared on the sound driver list.   After I un-installed it and re-booted....   SUCCESS!     In retrospect, I suppose I could have just disabled the device (without doing a real un-install) and had the positive result.

  My sincere thanks for the tips and help.   I had been racking my brain for other programs - checking the sound drivers was the key...

  Again, thank you.    Looking forward to giving your demo a real try now.

did you ever magage to resolve your run time error 2147467259. I have this problem now. My pc is running fsx and vista. I have looked through the other postings on the site.

any thoughts would be appreciated......