Problem With Ports on LINKSYS?

Hello,

I have a MAC and a windows laptop connected to a LINKSYS WAG54G both using Ethernet.

For the past few weeks if I switch off the router at the mains when I switch it back on I occaisionally have to resotr the setting frm a backup file. That's fine (ish) but now it seems that it will only lt one machine connect at a time. If I am on the MAC and try and use my laptop I can see the router and use the 192.168.1.1 address to connect to it but I cant browse the web. Is my router gradually dying or am I missing something?
All help greatfuly received!