iOS5 Killed My Wifi

I thought about posting this in the iOS5 thread, but thought it more fitting here???

Before I updated to 5 on my iPhone 4, when I would run a speed test connected to my Airport Extreme, I would hit around 12 nearly every time. I tried today with iOS5 (iPhone), and was disappointed when the results were no better than my 3G service. My iPad (iOS5), however, is still hitting 15s.

Are there some setting that I am unaware of that need to be tweaked in order to run my iOS5 device at the wifi speed I used to get before updating?