Just tried it out again ... the issue on the right half of the screen is largely gone, but now it appears to have relocated to the bottom half of the screen. There does seem to be some improvement, though, because I can navigate the site somewhat now whereas before it was very difficult. It's definitely the Amazon ad, not any of the others.
I'm wondering if this is a Droid issue or an all around smartphone issue - do any iphone or Blackberry users have this issue? One thing's for sure, please don't remove any ads on my account due to this.