VirtualBox keeps crashing Windows XP/7 VMs

[Djihed]

Virtualbox keeps crashing my windows 7 and windows XP VMs.

This problem doesn't happen on Linux Guests.

Attached is a virtualbox log file when this happened.

I have tried disabling 2D and 3D acceleration with no luch. I have vbox additions on both VMs installed.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: virtualbox 4.1.12-dfsg-2ubuntu0.5
ProcVersionSignature: Ubuntu 3.5.0-43.66~precise1-generic 3.5.7.23
Uname: Linux 3.5.0-43-generic x86_64
NonfreeKernelModules: symap_custom_3.5.0_43_generic_x86_64 symev_custom_3.5.0_43_generic_x86_64 nvidia
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Tue Dec 3 17:25:17 2013
InstallationMedia: Ubuntu 12.04.2 LTS "Precise Pangolin" - Release amd64 (20130213)
MarkForUpload: True
ProcEnviron:
 SHELL=/bin/bash
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 LANGUAGE=en_GB:en
SourcePackage: virtualbox
UpgradeStatus: No upgrade log present (probably fresh install)