Today I experienced a problem with Drupal's one time URL behaviour when resetting your password. I am a fan of the way Drupal does this, which I think is much better than most sites are handling password resets.
However in this particular case Drupal's solution failed to work. What happens is that the transparent proxy is making a connection to the URL (that I got by mail) and then does a second request that is actually going back to the browser. In a log, it looks like this: