When switching to the newznab tab, with the "Focus on search combo when switching tabs" option enabled, the search results pane gets focus rather than the combo box. Also, the "Auto focus on main control in tabs" option does not seem to function properly on the newznab tab (I don't use this option, but I noticed when testing it out).
One more nitpick: the Age column on the omgwtfnzbs and newznab tabs sorts in reverse order from other tabs (sort descending puts newest posts at the top, ascending puts oldest at the top when it should be vice versa).