I noticed the same problem, starting with the 6.9.2 update. When you start typing a tag name, the arrow keys would like you select from the autocompleted list. Resizing the window doesn't happen when using the arrow keys if the cursor is in the "add tag" field. This arrow-key election was the same behavior you still get in the main app when typing a tag name. That selection control is gone now, which makes tagging in the clipper slow enough to not be worth doing.