Hi,
yast2 rpm reinstalls I managed to get everything back. Then to see what broke Yast I ran another online update. The only packages that needed updating were Curl, Perl(5.8.3 I think) and Perl-DBI. After doing the update Yast broke again. I now get: "warning: the ncurses frontend is installed but does not work You need to install yast2-ncurses to use the YaST2 text mode interface".
I'm on 9.1, an saw this behaviour of yast already once! I updated to the (that time) newest ulb-gnome with solving the dependencies manually. I mean slowly and precisely, but doing most of the installation from command-line. When I tried to start up yast, it told me the same error-message. I was very upset with it, but after 4-5 longer google-session I found a single post on another mailing-list, where somebody suggested to be extremely careful with the ulb-stuff and mentioned as an example the curl (!) package. I reinstalled yast et al. already couple of times, so had nothing to lose. I navigated to the page of GURU and downloaded his curl packages: http://linux01.gwdg.de/~pbleser/rpm-navigation.php?cat=Network/curl/ Their installation solved my problem completely; yast is just perfect now. (I mean just as good as it was previously.) I don't think, that it's a solution for your problem, but just fyi, Pelibali