For anyone who has the problem that their 10.4 macs are unable to connect to their Linksys WRT54G router. then check out this thread in the linksys forums.
I upgraded my router to the latest firmware, everything was working fine, until I had to shutdown all my machines (for a pg&e scheduled power drop), on restart all the boxes came up but the macs couldn’t access the internet. Some time spent on frakking around revealed I was able to manually assign IP’s and DNS settings which pointed to a problem with DHCP.
It turns out the 1.01 firmware is broken for macs running OSX 10.4. you can downgrade the firmware in the router. to 1.00.9 but that might be a risk to some folks. so I have went with the alternative solution of manually assigning IP’s.
the firmware should be available from here. no news yet as to when Stinksys will be releasing a fixed version.