OS X Mountain Lion incompatible with Asus RT N66U router?

I've been using my early 2009 Macbook Pro with OS X Lion on my Asus RT N66U router for about a month now and have had no problems.

After upgrading to OSX Mountain Lion, I began getting timeouts on a number of websites, including:

* Facebook

* Hulu

* Youtube

* discussions.apple.com

On most of these sites I can usually access the front page after clearing the browser cache, but whenever I try any link from the main page (e.g. try to navigate to my profile in FB) the browser hangs until it times out.

This happens across all browsers. I tried Chrome, Safari, FIrefox, and Opera.

It also occurs via wireless and wired connections to the router.

I also have a Windows 7 desktop in the house, so I tried that with the same wireless network and all the websites worked fine. I had my girlfriend try connecting with her Macbook pro and Lion, and she was also able to access all those sites.

Thinking there was a problem with my Mountain Lion upgrade, I decided to try a different router to be sure. I configured my old TIme Capsule in place of the N66U and with that, Mountain Lion was working like a charm. Every one of the websites above was working fine.

I'm fresh out of ideas. I'm thinking either:

1. There is some default configuration in the N66U that Mountain Lion doesn't like.

2. Something *did* go wrong with my upgrade, but the problem only manifests itself with the N66U router.

3. There's some funamental incompatibility with Mountain Lion and the N66U

Thoughts? Suggestions?

Thanks!