additional note: the problem occured when the kernel packages were upgraded from the kubuntu update notifier. It had displayed only these two packages to be upgraded.
I resolved the problem and got to the previous state by uninstalling the unconfigured packages, then installing the older kernel packages with 'apt-get install linux-generic=2.6.31.20.33 linux-image-generic=2.6.31.20.33'
Then doing 'apt-get dist-upgrade' installed the new kernel packages and additionally the packages grub-common
grub-pc
additional note: the problem occured when the kernel packages were upgraded from the kubuntu update notifier. It had displayed only these two packages to be upgraded.
I resolved the problem and got to the previous state by uninstalling the unconfigured packages, then installing the older kernel packages with 'apt-get install linux-generic= 2.6.31. 20.33 linux-image- generic= 2.6.31. 20.33'
Then doing 'apt-get dist-upgrade' installed the new kernel packages and additionally the packages grub-common
grub-pc