Rss feed settings

Hi,

I'm requesting an RSS feed of successful builds like this:

http://<servername>/guestAuth/feed.html?buildTypeId=bt134&itemsType=builds&buildStatus=successful&userKey=guest

But this appears to be limited in range to a recent date. The results contain this text:

Successful builds of [X] build configuration(s) of TeamCity server at http://<server>. (no more then 100 items, only for items since 24-Apr-2010) 2010-04-29T09:53:55Z TeamCity server 2010-04-29T09:53:55Z

Does anyone know how to request results from a date further in the past? How is this date range arrived at?

Thanks,
Jamie.