First, I know that we spoiled you guys by usually replying within minutes after posting, but that shouldn't be taken for GRANTED, and start complaining if you haven't got answer in a few HOURS, on a Saturday!
In any case, I managed to download and install the scenery (the trial version), and tested your exact situation, and there were no problems whatsoever.
It's possible you are missing some liveries. If you installed the Stand-Alone Addon manager to update GSX to the current version, it should have downloaded the optional liveries installer but, if it didn't, you can download and install it manually, the link is just above in the forum.
Or, you can download the full GSX installer again. It's the same.