The problem appears to be solved for the moment, though I no longer have LabView 8 on my development computer. Not a problem, I detest LabView.
I tried to selectively uninstalling Max 4.0 and re-installing Max 4.0 -- same issues, no GPIB hardware listed, and no software listed.
I tried to selectively uninstalling Max 4.0 and re-installing Max 3.1.1 -- same issues, no GPIB hardware listed, and no software listed.
So I deleted all NI software from my development computer, re-installed LabWindows Base 8, and the driver distribution CD. This installed Max 4.0. It worked fine -- GPIB devices and software listed in Max.
I installed FieldPoint 5.0 from a CD I burned from the website download. Prior to Restart, GPIB devices and software were not listed. After restart, all of the above are listed, and my GPIB applications work fine.
I don't know if something go corrupted along the way, or there is some incompatibility problem with LW8, LV8, FP5 causing Max to break. At any rate, it works now.
Thanks to those who helped...