Yeah for sure CraftyC, I have forgot the file mplayer-0.90pre10-1.i686.rpm and have used mencoder-0.90pre10-1.i386.rpm instead. Oops
(For everyone's benefit

The proper sequence to install MPlayer is as follows:
(Note: these files are common to every processor. To find packages which are optimized for the particular processor (in my case - PII), go to the page
http://mirrors.sctpc.com/dominik/linux/pkgs/mplayer and scroll down to have a look.)
Download:
http://mirrors.sctpc.com/dominik/lin...e10-1.i386.rpm
http://mirrors.sctpc.com/dominik/lin...e10-1.i386.rpm
http://mirrors.sctpc.com/dominik/lin...e10-1.i386.rpm
http://mirrors.sctpc.com/dominik/lin...0-1.noarch.rpm
http://mirrors.sctpc.com/dominik/lin...e10-1.i386.rpm (optional)
Install them like this:
rpm -ivh mplayer-common-<version>.i386.rpm mplayer-<version>.i386.rpm mplayer-font-iso1-1.0-1.noarch.rpm
rpm -ivh mplayer-0.90pre10-1.i386.rpm
rpm -ivh mplayer-gui-0.90pre10-1.i386.rpm
rpm -ivh mencoder-0.90pre10-1.i386.rpm (optional)
*TESTING*
I tried installing but an error came like this:
[root@localhost mplayer]# rpm -ivh mplayer-common-0.90pre10-1.i686.rpm mplayer-0.90pre10-1.i686.rpm mplayer-font-iso1-1.0-1.noarch.rpm
error: failed dependencies:
libpng.so.2 is needed by mplayer-0.90pre10-1
[root@localhost mplayer]#
But I have libpng.so.3 installed in /usr/lib/

And I am running Mandrake Linux 9.0