Matze,

Since you say it works in VATSIM, I have to believe by "normal" you mean the GameSpy multiplayer.

Unfortunately I have no reply for that scenario, as I don't use it.

But, I do use CS757 with FSHostClient to connect to the UGT FSHost server (where you fly with FS9 and FSX pilots) and this mode doesn't have all the extra bits like cockpit sharing or ATC or the like.

It works 100% for me in this scenario, so I know that FSHost and now you're confirmation VATSIM MP modes both work, so I don't know what could be with the GameSpy MP mode, but like CS says, they don't support it, so maybe there's extra things that do not communicate between cockpits or with ATC or something.

Besides, even though I never used GameSpy MP mode on FSX, I did use "The Zone" on FS9, and from what I heard, the GameSpy MP mode is much the same.  Just kids "playing a game".  That's not what I look for in FS, I look for proper simulation of flight... so I won't bother, though cockpit sharing mode sounds interesting!  :)