Recently upgraded the firmware of my Linksys wireless router (WRT54G) to v1.00.10 and cost me 2 days in finding out what the hack was happening.
Once upgrade, only my Mac no longer be able to connect to anything online becuase it wasn’t assigned no IP address. My wife’s IBM notebook is working ok.
Later I found out that its the firmware causing all these trouble from Linksys forum. So until there anything fix out there. You would rather stick to v1.00.9 instead.
Download v1.00.9 firmware is available from their FTP.