Upgrading probs 9.0-> 9.1

Hi, I yesterday upgraded a number of machines with a few problems that I managed to solve. However, one I could not solve: This machine did the upgrade perfectly, but when I want to to the "online updatring" in Yast, it reckons it is still 9.0. When I then try to do a "system update" again, it says that there are 2 packages to be updated, says it does the upgrade, but same problem. And when one then again tries to do "system update", 2 packages needs to be updated. KDE is upgrade - no problem. What do I have to do to persuade the machine that it is indeed upgraded? Thanks Nico