Thru put has dropped and WiFi connection irregular

I don’t know if this has been caused by the latest Leopard Security update 2008-005 conflicting with ATV Flash (v3.2), but suddenly my connection with an Airport Extreme ‘n’ router has taken a huge hit, including dropping off of the network completely. I went from 5 solid bars to a max of 3 bars, reported by the ATV. From a desktop machine running Airport Utility, the statistics option shows a rate of only 10 for the ATV (a version 2, updated to 2.0.2) whereas a MacBookPro near the ATV shows a rate of 120. Trying to FTP to the ATV gets only 100kB/sec where it used to get 6MB/sec!

Anyone else see this kind of problem after upgrading to Security 2008-005?

It doesn’t appear to be a problem with the ATV alone as I can connect to a neighbor’s router at a full 5 bars of strength. So it might be something to do with the Extreme and the ATV after the security update.

Apple’s support sites contain reports from other ATV users (in addition to my experience) that their internet connections to Extreme routers have taken a serious performance hit when they upgraded to Security update 2008-005 and iTunes 7.7.1. FTP speeds don’t go above 150kB/sec any more. Has this happened to anyone else?