The version of VirtualBox in Ubuntu 10.04 does not support kernel 2.6.38 (used in Ubuntu 11.04). If you require kernel 2.6.38+ and VirtualBox at the same time, then you will need to upgrade to Ubuntu 11.04 or 11.10.
The version of VirtualBox in Ubuntu 10.04 does not support kernel 2.6.38 (used in Ubuntu 11.04). If you require kernel 2.6.38+ and VirtualBox at the same time, then you will need to upgrade to Ubuntu 11.04 or 11.10.