Calibre Advice

[the-other-sandy.livejournal.com]

Last week, I used the FanFictionDL plugin in Calibre to create an anthology epub of a series on AO3. Everything went fine. This week, the author added a new story to that series. I was able to use FanFictionDL to update the anthology epub, but I can't get the Count Pages plugin to update the new page total. I get an error message that says "Book already has all statistics and overwrite is turned off." I've been through all the settings in FanFictionDL, Count Pages, EpubMerge, and Calibre itself, but I can't figure out where it thinks I'm telling it not to overwrite the page count. Any of you Calibre power users know what I'm doing wrong?