I have a patron list, that shows 3 patrons on the list, when it actually is only one patron. I tried reproducing the problem, but so far couldn't. The count is corrected, if you delete a patron that is on a list, so that doesn't seem to be the problem. My table patron_list_patrons shows only one entry for the list - still the count is 3 on the patron list summary screen.
*** This bug has been marked as a duplicate of bug 11857 ***