I wanna thanks Micheal 2. I installed FC6 two weaks ago and some new diagnostics in Xorg 7.1 informed me the Quadro NVS 400 I'd been unseccessfully trying to make play with Nvidia's drivers was basically hardware toast, not a driver problem. Based on redblog I bought an x700 open-box special from NewEgg, and it works fine, albeit Bigdesktop only spans two displays (but I couldn't afford a new Quadro and the x700 price was right.)
One Livna issue that kinda surprised me: I was originally running kernel 2.6.17-1.2139_FC5, upon which Livna's kmod-fglrx 22.214.171.124_1.2157_FC5 (8.26.18) installed just fine Just FYI and something to watch out for. Be sure to run "uname -a" and "yum info kmod-fglrx" before doing "yum install fglrx" to make certain yer vmlinuz and yer fglrx are both reading from the same page. Don't count on yer yum checkin' it for you.