I had a production issue today where delivery of a handful of update statements failed at the subscriber with "row not found". What's odd about it is that I have a horizontal filter set up on the article in question such that the rows in question shouldn't have been at the subscriber. What's especially odd is that there were many other rows within the same transaction that also qualified for exclusion via the filter that didn't trigger the same error. I got past it by setting the distribution agent to ignore errors. Does anyone have any idea what happened and how I can keep it from happening in the future?