I just set up the dir-826l, and an iphone, Blackberry, and HP Win7 laptop all connect to the 2.4GHz SSID (with the lappy also connecting to the 5GHz SSID) quickly and easily.
The Ubuntu PC, however, will not connect. I have a USB G dongle, which worked perfectly fine with the 2.4GHz Linksys router I've been using up until 20 minutes ago.
Any ideas? Switch to dedicated channel? Switch to G and N, only?