Forum Moderators: martinibuster
An important question: Is this just your experience, or does everyone who looks at your site see the same slowdown?
I would guess it's just you, because we're not seeing a similar problem, and because of the way you've narrowed the problem down to pagead2 and not pagead1, it sounds like a DNS resolution problem, which takes place at the client end (the web site end user) and has nothing to do with your web server or anything related to it (like your webserver's backbone access, etc.)
The first thing I would do is open a command window on the same machine you're seeing the slowness and try pinging pagead2.googlesyndication.com.