Hi Andre,
SIT & UAT would be your development and test environments, each on a separate computer, Production is the environment where you have problems, and I assume this is yet another computer. With verified and correct versions of BP, the processes and the applications, and the problem occurring only in the production environment, the cause might be an environment issue in the production environment, one of which could be a different screen resolution on the production computer.
------------------------------
Happy coding!
---------------
Paul
Sweden
------------------------------
Happy coding!
Paul, Sweden
(By all means, do not mark this as the best answer!)