High CPU used by NS.EXE

I installed Norton Security last week, replacing Norton 360.  This is on Win/XP SP3.  This machine runs several Servers that receive remote connections.  Everything runs slowly now so I am looking at the Windows Task Manager.  The CPU is running 80-100% (Intel core2 CPU 4300 1.8 Ghz).  The process NS.EXE is constantly using 30+% of the CPU.  With no applications running my machine now idles at around 50% CPU.  With the Servers up, at times socket connections cannot be made or existing connections are dropped.  I have tried turning off all the various parts of Norton Security with no change.  When I use Task Manager to kill the ns.exe process the CPU immediately drops to normal levels and everything runs fine but of course I have no security.  I don't see this problem on my Win7 machines.  Are there any settings that might help me, or am I just going to have to uninstall this thing?