User blog comment:Neeeeeeenja7/Backpack SDU question? Please answer!/@comment-1945804-20100507064620

Lockdown Palace doesn't yield an SDU on any Playthrough. As far as I know, SDU's can only be gained in Playthroughs 1 and, less commonly, 2, in the main game. There are only ten Claptrap Rescue Missions in the main game: 12 + (10 * 3) == 42.