I've currently got a Macbook and a Macbook Air connecting to an Airport Extreme Basestation with the new firmware. Both the Macbooks have 802.11n and the new Airport Utility installed. My Macbook is functioning perfectly, however, my Macbook Air has the following problems: 1) It won't connect to the AE when it is set in the 802.11n only mode at 5 GHz. It will scan for the network but not find it. It will connect in the 802.11 only mode at 2.4 GHz. 2) It prints very slowly to my HP printer connect to the AE via the USB port. It will spool the page being printed and will take about 1-2 minutes before the printer finally print it. My Macbook doesn't have any problems printing. When connected directly to the printer, the Macbook Air prints fine making me think that this is a networking issue. I believe the printing problems started after the upgrade, but since I use my Macbook more than my Macbook Air, I could be wrong about this. I've tried the following on my Macbook and Airport: -Reinstalling the printer drivers on the Macbook Air. -"Reinstalling" the Airport card via Network Utility on the Macbook Air. -Changing the AE setting to include "Interference Robustness" or "Wide Channels" -Turning off IPv6 on the Macbook Air TCP settings (suggested by another forum). None of these things seem to work. Interestingly, the internet connection is good and the download speed from my AirDisk is also good on my Macbook Air. The only issue I have is with the printing.