10.4.8 upgrade: lost connection to wireless router

[what4]

Since upgrading to 10.4.8, I can't connect to my normally trusty wireless router. I've reconfigured the router, gone back over the internet and network connections, to no avail. Any ideas? The router has no firmware upgrade listed, so that's not the problem.

Later today, I'll try it on a different wireless network, to see if that works.

Router: Belkin F5D6231-4

Computer: PowerBook G4, aluminium 1.67

Thanks for any ideas.