at the fist boot after upgrade I did have the non-proprietary driver, at least I think so, it was the dirver for ati x1300-somethingelse family, which I also used when I first installed mandriva, before installing dkms-ati. (is this the non-proprietary driver?I think so because it was in the free mandriva isntallation dvd, but if not, which one should I choose?)
in this situation I tried both the new and old kernel, but it was always not working.
as this did not work I uninstalled and reinstalled dkms ati with the new kernel source... I know it's stupid, but I didn't know how to simply compile the drivers! just don't know the commands!