cursor causes graphical glitches in the GUI

Whenever I enable screen offloading with my two muxless hybrid graphic cards (http://nouveau.freedesktop.org/wiki/Optimus/) with xorg 1.15.1-1 / xrandr 1.4.2-2 , I see graphical glitches in the mouse cursor in QT4 and QT5 applications. GTK applications do not have this issue and also when running with only one graphic card, then the graphical glitches in the mouse cursor won't show in the QT4/5 applications.

Attached are pictures of my screen (I could not enable showing the pointer within a screenshot) with qcad (QT4), QucZilla (QT5), and VirtualBox, where this glitch is most annoying.