Strange video effect with Qtractor and CALF plugins

Hi Rui,

as you wrote that you will drop qt4 support eventually I installed qt5 (5.2.1) on Ubuntu 14.04 and recompiled lilv, vee-one, qtractor, CALF.

When I open a CALF plugin then it seems to claim a rectangle of its own size as long as it is open that behaves like a window on top with some garbage of the underlying window in it. As soon as I close the CALF plugin it restores to normal behaviour.

Please see the screencast http://marzen.de/tmp/b.mkv

Any idea?