Forget Yast.
Seriously, these pacakage management apps... they all out to be put on one disk and formatted.
It is really easy to install MySQL yourself - I did it on FC3 with no problems. Go to the mysql site and download a "standard" binary version for your system. I've got
mysql-standard-5.0.26-linux-i686.tar.gz
for my P4 based 2.6.14.3 FC3 system. Then follow the seven step instruction list in the package directory after ungzipping it. Works beautifully.
Nothing against SUSE or Yast as such, just experience that indicates that these "helpful" installation apps usually cause more problems than they solve.