BEFSR41 firmware update

My BEFSR41 v 2 has firmware 1.39 (from 2001). I want to use it to extend my network from or to a WRT54G. I have it plugged into the WRT, and one computer into it. It works fine, but I can't get it to keep a new IP, I can't turn off DHCP, I can't switch from gateway to router and have any of these changes stay. I can save them and the BEFSR accepts them and indicates success, but it always reverts to its native state?!? So, I want to do a firmware update, BUT this version has a built-in updater that will only start a Java script that attempts to connect and download the update - with no success. I have several bin files with newer firmware versions, but cannot install them. Linksys is no help, as usual their techies don't understand the words coming out of my mouth. So, any thougths or help would be most appreciated. Thank you. Bruce North