Twitter Search API

I am trying to find only new tweets using Twitter Search. For example:

http://search.twitter.com/search?tag=bruins&lang=en&rpp=100&result_type=recent&since=22451745267388417

does not pull any tweets, however, if you remove the since portion, there are tweets that have o开发者_如何学Goccurred more recently.

My question is this. What am I doing wrong? Given the documentation located here, I feel like I am following their guidelines.

The documentation states:

since: Optional. Returns tweets with since the given date.  Date should be formatted as YYYY-MM-DD
Example: http://search.twitter.com/search.atom?q=twitter&since=2010-02-28

So you should be using:

http://search.twitter.com/search?tag=bruins&lang=en&rpp=100&result_type=recent&since=2010-12-31