To uninstall you should actually do:
(Assuming you are in /root/mplayer)
[root@localhost mplayer]# rpm -e mplayer-gui-0.90pre10-1
[root@localhost mplayer]# rpm -e mplayer-skin-default-1.5-1
[root@localhost mplayer]# rpm -e mplayer-font-iso1-1.0-1
[root@localhost mplayer]# rpm -e mencoder-0.90pre10-1
[root@localhost mplayer]# rpm -e mplayer-0.90pre10-1
[root@localhost mplayer]# rpm -e mencoder-0.90pre10-1
Just a correction
We have to get rid of the whole
.i386.rpm 
Hybrid Mode
