Norton AntiVirus (NAV) has the ability to detect unknown viruses of various types using heuristic algorithms known as Bloodhound. This technology was developed by Symantec Security Response.
You state that Norton is rejected access to repair it, which would lead me to believe that it is possibly inside a System Restore file. In that case, disabling System Restore will remove it.
I've got the virus (bloodhound.w32.ep) on one of my computers. Norton tells me I have it but doesn't find it when I do a scan, and it says it is rejected access to repair it. Does anyone know how to get rid of it.