delta-fetch not scraping new items

[clpatterson]

When I run an initial scrape with delta-fetch enabled it tells me that it has stored 263 urls where items have been scraped. I assume when I run it again I should see 263 log lines with info about urls being ignored as well as any newly scraped items, but instead delta-fetch says 14 random urls where ignored and closes. Any suggestions on how to debug this issue would be greatly appreciated!

Please see my stackoverflow question here.