VirtualBox 4.2.16 terminates KDE session

I can launch VirtualBox but any attempt to open VM's settings or run VM terminates my session and I'm presented with the login screen. This happens with old (and previously working) VMs and brand new ones.

Any clue will be appreciated :)

Version details: VirtualBox 4.2.16-85.5 from

Index of /repositories/Virtualization/openSUSE_12.3

OpenSUSE 12.3 x86-64 desktop kernel

KDE 4.10.5