YaST fails to start

I just upgraded to SuSE 9.1 and everything seems to be working fine except YaST. If I try to run it. It verifies my root password and then doesn't load. If I try to run it via the control center, I can select a module and put in my password, but the module doesn't load. SuSE online update fails with a log notice that it can't find libpopt.so.0. Running YaST in the console results in a message that the text version is installed but not working. I've tried forcing an reinstall of popt-devel, and of various of the YaST packages with no luck. Any thoughts? Thanks Hilary