Was helping a friend trouble shoot an old Linksys WRT-54G Version 2.0 and I thought it might be worth installing the Tomato firmware and see if it helps minimize the connection drop outs he’s been having.  I thought upgrading via the Linksys admin menu would be a snap.  I made a couple of mistakes.

1) Always do a hard reset (30/30/30) on the router before flashing

2) Always hard wire and set a static IP that is within the default range and turn off all other network cards

3) Be patient, because sometimes it’ll take a few minutes

What happened was this: the upgrade from the Linksys admin utility resulted in a corrupt image such that I was no longer receiving an IP address, the router was not booting, all I got was a flashing green power LED.  Thankfully, Draytek Router Tools v.4.2.1 comes to the rescue with TFTP tool, as I tried the Linksys version of the software with no luck.  Router Tools allowed me to get the WRT-54G back online with the latest official Linksys Firmware v.4.21.1 and at this point I went back into the menu and tried the Tomato v.1.27 .bin again and it actually worked.

Now, whether all this means the router will stop being flaky, I don’t know.  But many other users swear by Tomato and say that it’s a significant improvement over the stock firmware and includes a lot of QOS features and should increase stability.

This is pretty much the best guide I found on recovering from a bad flash:
http://www.dd-wrt.com/wiki/index.php/Recover_from_a_Bad_Flash

This is the link for latest official Linksys firmware on the WRT54G:
http://homesupport.cisco.com/en-us/wireless/lbc/WRT54G/download

And if you click on Version 4.0 on the BEFSR41 router/hub you can download Linksys’ official TFTP tool, which probably won’t work and you’ll need to download the Draytek utility anyways:
http://homesupport.cisco.com/en-us/wireless/lbc/BEFSR41/download

Linksys WRT54G Version 2.0