Hi, I made up an rpm of ghostscript for RH7.2 with the patch (see https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=55772) applied which fixes the rendering problem with LyX preview figures.
If there is a place to put it, I can upload it somewhere. I have a .src.rpm (14.5Mb) and a .i386.rpm (7Mb). Ben.