The problem is caused by the screen setup in the program.
To fix the problem, you need to do the following:
1) Note your computer's desktop settings.
i.e. 1280 x 1024 for example.
2) Navigate to where you installed TS2010
i.e. C:\Program Files\Auran\TS2010 ---- your path maybe different than this.
3) Add in the following lines to the trainzoptions.txt file. You need use Notepad to edit the file. The numbers shown are examples. Put in your own values.
-width = 1280
-height = 1024
Save the file and close the folder.
4) Start Trainz
5) Go to Options then Video settings.
6) Set the video size using the scroll box to correspond to what you set in the trainzoptions.txt file.
The problem will be solved, and hopefully in upcoming versions, or after the next service pack.
John