Can you please stop believing it's only an Airport issue? Because it's not, or at least it's much more than that.
My Airport has been disabled for months and all the problems started a couple of weeks after installing Snow Leopard.
And it's not ATI related either (I don't have any).
Look mate, there are a ******** of problems with flash on macs, and always have been, but *this particular issue* is related to the Airport, as cycling it off and on in any way fixes the problem, which the video *clearly* shows. If its not fixing it for you, then you clearly have a completely separate issue thats manifesting in the same way, which is likely as the problems for you sound like they started well before this new product line.
I too have been working with the Apple engineer (same one most likely, as have others) to debug this problem on and off for the last 10 hours or so. No solid answers yet though.