Comment # 1 on bug 898639 from Bernhard Wiedemann

tried unsuccessfully to reproduce on 12.3 Host with
virtualbox-host-kmp-desktop-4.2.6_k3.7.10_1.11-3.6.11.x86_64
virtualbox-qt-4.2.6-3.6.11.x86_64
virtualbox-4.2.6-3.6.11.x86_64

with openSUSE-13.2-DVD-Build0011-x86_64.iso (13.2-Beta)
and default KDE install on a 8GB virtual disk

Network: Intel Pro/1000 MT
SATA-Controller AHCI + IDE PIIX4
no graphics accelleration (12MB graphics RAM)

you could try varying the graphics settings
and if some change would make it work, that would give a good hint
towards where the problem lies.