virtualbox.org

I am using VirtualBox with Siemens PLC programming software, and has been doing it for a while.
I has been working fine with no flaws until rev. 4.0.x

Now the Siemens software makes VirtualBox chrash to Splash screen without any warning.
When reverting to 3.1.2 it runs flawless again.

Guest additions are of cause updated i the same rate as VirtualBox

Any ideas why ?

Always a good practice to search a forum before posting a problem.
One example here http://forums.virtualbox.org/viewtopic.php?f=2&t=28932&
Seems it is bug in the display driver where the new version has preview in the GUI.
As I recall, it is possible the disable the preview, which might solve the problem.
I as well had huge problems with the upgrade, and has reverted to previous version.