I've been working on my development machine to get it the way I wanted. When I started working on the GIO functions of gnome-mplayer I needed to upgrade to Fedora 9 so that I could get the libraries. It was working ok, but what I really wanted was to run in 64bit mode on my machine, since I do have 4GB of RAM and a 64bit CPU.
So I reinstalled the x86_64 version of Fedora 9. However, I still wanted to be able to run a few 32bit apps. One is my scanner driver and the other is mplayer. The 32bit version of mplayer has a few more codecs than the 64bit version so I wanted to have that. My first test was to get everything I needed from livna and setup the basics. I decided that I would first install mplayer.i386 from livna to make sure I had all the right basics. To do this I had to edit my fedora, fedora-updates and livna repo files. I copied the base setup to a new [fedora-i386] for example and then made sure I was getting the 32bit files. I then installed mplayer.i386 and mencoder.i386. I then rebuild gnome-mplayer in 64bit mode and made sure that all that was working.
So far my 64/32 setup is working ok. And it already helped me fix a minor install bug in gecko-mediaplayer.