(this is example, has no reflection to current state ...)
EPEL provides xmms-1.2.10-1.i586.rpm - but without MP3, WMA, AAC ... DAG provides xmms-1.2.9-1.rf.i586.rpm - with all those beasts ATRPM provides xmms-1.2.10-1.at.i586.rpm - with all those beasts
Which you installs? Who knows, probably EPEL ...
Solution?
Repo priorities and includes
But wouldn't it be easier if the packages had different names so you could just install the one(s) you want from the command line?
Please suggest an easy to handle inter repo clean system how to rename XMMS packages on top of this page .