Comment 15 for bug 1264821

If you have 2 videocards e.g.
01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Turks [Radeon HD 6670]
02:00.0 VGA compatible controller: NVIDIA Corporation GF106 [GeForce GTS 450] (rev a1)

And configured two screens e.g. :0.0 and :0.1 locker-qml will lock only one screen

Reproducible: Always