I restarted my most recent project to get to the bottom of why it does not work in a Linux environment. I have narrowed it down to the mouse being the problem. When the mouse is grabbed, I contantly set the mouse position to half of the width and height, but Linux seems to completely ignore this statement.
Mouse.setCursorPosition((int) orth.getWidth() / 2, (int) orth.getHeight() / 2);
If I grab the mouse in windows, move around, and un-grab the mouse, the cursor is at the center of the screen. But if I do this in Linux (Ubuntu) my cursor just moves about like I never called the setCursorPosition method. Is this a known bug?