I can't see air traffic in FS9..know why?

Hi, apologies if this question was already asked! While I was holding short and waiting for a 777 take-off, the 777 actually made a beautiful run on the runway, took off and started to climb, and after 3-4 seconds...disappeared in the thin air!Also, during flight I get calls from ATC in order to spot traffic nearby, but I can never see any of it, while in 2002 I used to enjoy the company of many fellow aviators in the skies.I imagine that may be some settings need to be changed, in order to improve the radius within which the AI can be seen. I thank in advance for any suggestion :-)Sergio.