When you build MPlayer, make sure you have the --enable-gui flag set
with configure, such as:
Also, you might want to make sure you have xorg-x11-devel package
installed on your Fedora machine (that is what it was called in FC2)
before you run configure, etc..
yum list xorg-x11-devel
If it is in the Available packages and not in the installed packages,
then install it using:
yum install xorg-x11-devel
Hope this helps!