Some known problems...

• In case you try to fly the complete mission in one pass (with time acceleration, of course ;-) your re-entry will "fail" and you will miss Baikonur by 1200 km. Using powered flight back to the base is quite fuel consuming and you can end up miles away without any fuel left...

• If you try to use the Orbiter built-in version of the Atlantis SpaceShuttle, there is a weired behaviour at launch time when you are in cockipt view: All engines are at full thrust but the Shuttle just sits there like a drunken duck - no lift-off. Workaround: Just switch to outside view (F1) and switch back to cockpit view - the Shuttle will now lift off the launch pad.