As the note says, I have been having this problem, and one of the guys on the Flynet forum has suggested opening flynet.ini in the c:\windows directory and changing the "tracker" value from "1" to "0".
I'm just testing it now myself, but he seems to think it would work.
Oh... and make sure your running the latest version of fsuipc.dll
[edit]
This seems to work fine. The only thing that is affected by changing this value is that the website doesn't show the aircraft as "boarding" while your on the ground. Everything else works normally.
Flynet Client Hanging on long flights
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