Virtualbox problems after reboot in Ubuntu

When you reboot after Ubuntu kernel updates, Virtualbox may have difficulties starting up.

If you get the error:
"[...]The character device /dev/vboxdrv does not exist"

Try the second solution in the following discussion link:

http://askubuntu.com/questions/71441/virtualbox-ubuntu-11-10-linux-kernel-3-cannot-start-virtual-machine

I just wanted to share this information with you just in case you face a similar problem.

Evi