How did the firmware upgrade go? I personally use D-Link network hardware, because I have had the best success (err, luck I guess) with them. Everyone that I know that has a Linksys router, has issues with them, so I avoid their brand like the plague. My family's router will stop responding randomly and need a reboot. Sometimes it will say no more available address when there are 3 being used, and over 40 left available in the DHCP pool. My girl's parents Linksys refuses to work with any form of wireless encryption. Well, I got it to work with ONE D-Link USB dongle (I avoid wireless USB too), but the Linksys Cards wouldn't work... lol.. .sorry [/soapbox]
The firmware upgrade should be faily simple. just a matter of downloading the file, usually they are pretty small too. Then you go to the router configuration page, login, and search through the tabs for the firmware section. MAKE SURE WHEN YOU UPGRADE THE FIRMWARE, IT IS WITH A WIRED HOST. If you use a wireless host to do the upgrade, you run the risk of bricking the router any packets are lost or corrupted or anything...
Let us know how it goes!!