Hi Troy,
immediately after installing mysql-server-5.0.45-7.el5 and calling 
`/etc/init.d/mysqld start`, it complains that there's no user:group 
mysql:mysql, which is indeed the case on a freshly installed box.

This was the output of `yum install` command:

Installing: mysql-server                 ####################### [10/11]
warning: user mysql does not exist - using root
warning: user mysql does not exist - using root
warning: user mysql does not exist - using root

Although this box was converted to LDAP using a custom cfengine setup, 
other RPMs (httpd) create their users without any problems.

Cheers,
-jkt