<server>.local not working on wireless connections to netgear router

[Colin Law]

I have recently changed my modem/router from a Linksys to a Netgear
DG834G v3.  Prior to the change I could access other machines on my
local network using <machine_name>.local.  Now, however, I can only
access machines connected to the router by wired connection and not
those on the wifi.  The command
avahi-browse -at
shows the wired ones but not the wireless.  I can't see anything
relevant in the router config (but I may have missed something).

Has anyone any suggestions?

Colin