Ah! With FS2002, the automatic joining of your session to a multiplayer session does not work in either Squawkbox or FSInn, because it is a feature only introduced in FS2004.
For FS2002 You have to create the multiplayer session manually and join FSInn to it.
The FSInn manual says, on page 11. [Quote]With FS 2002, you must make the multiplayer connection manually, ‘Flights/Multiplayer/Connect’ and enter the IP address 127.0.0.1 or localhost
I suspect that if you are doing this on two PCs, though, instead of 127.0.0.1, you have to enter the internal IP of the PC running FS, which is commonly something like 192.168.1.2. It is also necessary that FSInn cannot find a copy of FS9.exe on the remote PC. If you have FS installed on both PCs, you must rename FS9.exe to something esle on the remote PC before attempting to install FSInn on the remote PC, otherwise it will find the wrong instance of FS9.exe, and refuse to look elsewhere. In my view this is a bug/undesirable feature, and I have reported it on the FSInn forum.