The room in question is 129 by 152 inches or 10.75 by 12.667 feet and about 9 feet high (good old victorian building)
As it is victorian it has these massive bay windows which I'm guessing aren't too good for sound reflection
I can't physically alter the room, so no funky building stuff unfortunately
This first picture is the rooms current layout:

This second picture is a layout I'm thinking of trying out

I'm not sure what sort of treatment I could do to the room to improve its mixing and recording performance
So any suggestions are very much welcomed, in fact they are what I'm here for
If there is anything I have forgotten please let me know
I've also attached the sketchup files if you want to have a look, they are very crude though, as I've never used it before and only got it to show you folks in the know
http://www.mediafire.com/?oh5hq8ldk9eooff