ndiswrapper broken after upgrading to ubuntu 12.04: FATAL module ndiswrapper not found

After upgrading from 10.04 to 12.04 via shell (# do-release-upgrade) everything went well, except the network access...
(Networking was not integrated on my old sony z600, so i had to use an USB WLAN stick via ndiswrapper).

So what is wrong?
First i tried

sudo ndiswrapper -l

and this look quite good. Driver and hardware present.
Next:

sudo modprobe ndiswrapper
FATAL: Module ndiswrapper not found

Ok, with version 12.04 a new kernel is shipped (3.?) and this does not recognize the ndiswrapper.ko kernel module.
After running

sudo depmod -a

still the same problem...
But then i did

sudo apt-get install ndiswrapper-dkms

Now everything went well:

sudo modprobe ndiswrapper && sudo ndiswrapper -ma

and the network was up again and after a reboot it was still working....