if your system is anything like mine from mandrake, there is a load of software installed on your system that is not in the menu!
first try and find the installed package by trying variations like this:
or look into your /usr/bin directory and scroll down to the r's and see if there is anything there that looks like it might start up the real player.
anything in this directory can be typed into the console to be started. Actually getting it into the menu depends on whether you are using kde or gnome or something else.
if all that fails, you can issue the rpm command with a -f for force or it might be --force. you can find out by typing "man rpm" in a console window and reading about the options. anyway, the force option makes it install even if it already is.