I don't think restarting calibre has anything to do with it. I think it's a matter of TtH's author page(s) being out of sync or something for a while when a story is updated. But I need to see it before I can fix it--assuming I can.
I've uploaded
a new debug version on the earlier post that dumps the auth page(s) to the debug log. If I can see a copy of a debug log from this version with the problem occurring it should help.