I sat down tonight to do a quick, 5 minute update of the firmware on my Airport Extreme router to the latest revision, 7.5.2. I should have known better; never update a system that’s working perfectly well! I did the update of the Airport Extreme and the network-extending Airport Express, and both seemed to go well. However, I noticed that I had very sluggish connectivity. I have the Airport Extreme plugged in behind my ATT U-verse 2Wire router in DMZ configuration, so I tried a wired connection to the 2Wire to check on possible ATT problems. Working like a champ. Smokin’, in fact. Hmmmm….I googled on problems with this firmware update and came up with a number of hits and found a forum entry on the Apple site to be spot on. I hooked up a laptop with wireless active and a wired link to the 2Wire gateway, and downgraded the firmware back to 7.4.2. Worked like a champ. My speculation is that my Airport Extreme is an old first generation Extreme, and that’s the difficulty. I do know that I won’t be updating the firmware on this again, unless it specifically addresses this issue.