Tab Control doesn't work under Linux


I have a very strange problem with tab controls that do not work under Linux.
What I have:
-Container with two tab controls and a many other components
-Container is placed 3x on a Window
-Xojo version 20013R4.1 and 2014R1
I can click on the tabs but nothing happens - only under Linux, under OS X and Windows it works! It doesn’t matter if If compile or run it.
I can’t reproduce it, if I make a new application with a component and control tabs it works.
Components inside of the tab like buttons are working (so it’s not disabled).

Unfortunately I can’t attach the project source code.

Any ideas on what this might be?