I haven't been working with yum for too long (though I like it!) so I can't give you anything specific. But have you determined if this is a yum or rpm issue? Maybe you should manually install one of ...

But if I use yum can I still install the webmin rpm and the webmin turtle firewall sepeartely or before I start yum? Without a graphical interface to tell me what packages are included in yum I have ...