I formatted my pc completely from 10.10 (32bit) to 11.04(64bit)

Everything works fine, except for virtualbox.
I accendently installed virtualbox OSE, but removed it to install the complete virtualbox from the oracle sources... I hope this is not the problem...
I tried to add my old virtual machines, but i get this error
Kernel driver not installed (rc=-1908)

The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing

'/etc/init.d/vboxdrv setup'

as root. Users of Ubuntu, Fedora or Mandriva should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.
When i go to /etc/init.d, i don't see the file vboxdrv
when i do the command, i get the following:
koenh@koenh-Kubuntu:/etc/init.d$ /etc/init.d/vboxdrv setup
bash: /etc/init.d/vboxdrv: No such file or directory
I allready remove and reinstalled virtualbox 4.0, but no luck.
Does anyone has an idea what the problem could be?