Hi Tomek.
Here's what worked for me (after much trial & error... and worrying Manu, CC, and Solarisaint to death)
1.) Go into the "tennis.ini" under "[3dEngine]" and change "dev mode" from "0" to "1"...
2.) Launch the game and start a match...
3.) When in the match, pause the game and press "F9" to get rid of the "line judges" (that are up in the air) as well as the second "chair umpire" (also up in the air to the right of your screenshot)
4.) While still paused in the "match", you can change or move the dimensions of the court (baselines, service lines and sidelines) by pressing the numbers 1,2,3,4,5,6,7,or 8...
With these numbers you can move the court dimensions up, down, forwards, backwards, and sideways 'til you get it set up right...
(you might want to check out "Moving The Camera" in Manutoo's "Data\HowToMod.html" to get a clearer idea of how to do this.

)
6.) Once you get the court set up like you want, then quit the match, exit the game, and go back to the "tennis.ini", where you'll then go back to the [3dEngine] and change the "dev mode" back to "0" from "1"...
After you have done this, re-launch the game and you should see the difference...

p.s. Solarisaint told me that this US Open court is only the 1st one that he created, so the "blue" areas of the court aren't quite right...check out his latest US Open court on his "youtube link" posted earlier in this topic...