Offset=1 not skipping the first result (but offset=2 does)

As the title says, I have a page view that displays a bunch of node teasers matching a taxonomy term, posted after 2005, and published=yes, sorted in descending order of publication date. I can't seem to find any other settings that would be relevant. I set the pager to 'Display all items" and then "All items, skip 1" (the first node). However, all results are returned. If I set the offset to 2, then the first item is correctly omitted. I don't have this problem with any of the attachments to this query. That is, offset=1 correctly omits the first result.

Any clues as to what may be going wrong?