Slow antivirus since Netgear 834

DEar Egg Spurts - Since setting up wireless net at home, my
antivirus/firewall "CA Ezarmor" takes 2-3 hours to scan two 80Mb maxtors
on "Base" machine (2600+, 512Mb XPPro). Used to run in around 30mins
before network. Spybot and AdAware report no probs, also
grc.com/Shields Up. Two other macines on network show no such delay
when using same AntiV.
Any suggestions gratefully received!
David in Norfolk UK

--
Those who hear not the music think the dancers mad...