Looks like I just registered a blog with a feed that contained 415 items. Neither item had a valid date. So my script just published them all. Sorry for the inconvenience, I have removed the offending items and also the feed now.
Note to self: Never again accept a feed from that particular photoblog host, or make the script stop at x items per feed per hour. Whichever takes less time.
And now back to our regular program.