It's all good. Fresh install of RedHat 7.2 (after finding the magic kernel flag "apic" so the install CD would finish booting), Nessus 1.2.1 installed from nessus-installer.sh is working now and saving output. Now on to figure out how to get this continuous scan thing working....
Thanks for all the help. --- "The avalanche has already begun. It is too late for the pebbles to vote." -- Kosh
