What do the syslog logs say?
Fedora Core 3 still uses MySQL 3.23, which is an old version. I'm trying to figure out how to upgrade it to MySQL 4.1.14. I got it to upgrade to version 4.0.25 just fine, but upgrading from there to 4.1.14 goes without a hitch until you try to start the mysql server. It fails every time. Any ideas on what I can do differently?