I use VirtualBox (not the OSE version) which I installed (following the instructions at www.virtualbox.org/wiki/Linux_Downloads) using this repository:
deb http://download.virtualbox.org/virtualbox/debian natty contrib
Up until Version 4.0.12 the software has updated automatically. Version 4.1 has just been released and, although I can see it in Synaptic, it doesn't seem to be recognized as an update to the previous version by Synaptic or by Update Manager.
Why is this, and is it safe to just install it alongside the previous version?