When starting an MITk application with QmitkRenderWindow instances, the render windows are only correctly initialized (i.e. with correct size information, DisplayGeometry etc.) when calling either
show() and showFullScreen()
or
show() and resize(x,y)
together. Otherwise, the render windows are initialized with wrong size information, and the displayed image is often quite distorted.
This could be a Qt problem, but maybe the problem is in QmitkRenderWindow itself.
Should check if in any way the problem can be solved by modifying QmitkRenderWindow (e.g. its constructor) with some Qt magic.