Get the latest firmware on your WRT54G. Look at the bottom of it and it should say 'WRT54G v6" .....or v2.2 or v9 or whatever. That take that version number and go to linksys.com, download firmware to your computer, log into the web interface of the router (usually
http://192.168.0.1). Take note of your settings on the WAN and wireless pages (taking screenshots is a quick/easy way to do this), and then go to the far tab on the right: admin. Upload the firmware, the router will restart and *hopefully* keep your network settings. If not, you have all the screenshots of your previous settings.
Do this all from your computer to your router with a hard cable if possible, otherwise when it reboots it may default to the wifi network 'Linksys'. Make sure you set up at least WEP but preferably WPA or WPA2 security.
Now make sure you can connect to the internet from your computer, then might need to reboot the PS3 and then test it out. Good luck!
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