How many people that can't see the AI have ProjectAI, Military AI Works, World of AI or similar packs installed?

If you have, then you may not be aware that a single FS8 format AI file (such as those from the above freeware developers) will block ALL the native FSX traffic from running. Aircraft and ships.

This still remains the most common reason for not seeing FSX AI traffic, by a long way (although it does presume that the CS AI traffic is in an FSX native file format, which I haven't checked yet...  ::) )

Ian P.