RSS totalItem limit?

Is there any particular reason why I would be limited to 1000 totalItems when paging through an RSS feed? I understand that the page size limit (quantity) is limited to 1000, but shouldn't I be able to get to page 2 w/ quantity = 1000? As soon as I try to request p=2&quantity=1000, I get a "Not Found" error.I know there are tens of thousands of total items. I NEED to be able to access more than just the most recent 1000.

For example: http://serve.a-feed.com/service/getFeed.kickAction?as=16878&p=1&quantity=300&media_type=photo&totalItems=5000 works, but as soon as I try to get page 4, I get an error: http://serve.a-feed.com/service/getFeed.kickAction?as=16878&p=4&quantity=300&media_type=photo&totalItems=5000

Is this a recent limitation? I seem to recall a few months ago being able to access as many items as I wanted as long as I didn't exceed 1000 per PAGE.

 

Our RSS feeds only offer 1000 results, regardless of how many pages these results are split up into.