virtualbox.org

When install Virtualbox 3.0 (last version) bash say:

* Starting VirtualBox kernel module
* modprobe vboxnetflt failed. Please use 'dmesg' to find out why


dmesg

[ 1444.881541] vboxdrv: Successfully loaded version 3.0.0 (interface 0x000e0000).
[ 1445.093507] vboxnetflt: disagrees about version of symbol SUPDrvLinuxIDC
[ 1445.093514] vboxnetflt: Unknown symbol SUPDrvLinuxIDC

Ubuntu 9.04

I solved with /etc/init.d/vboxdrv setup