This works, but your console log starts filling up with errors, one of which suggests it may be wasting resources doing extra redraws to work around the broken split view, so I reverted to the backup for now. I'm gonna mess around with it later and see if there's a cleaner way to do this.

6/26/08 09:07:56 Safari[60303] : the delegate was sent -splitView:resizeSubviewsWithOldSize: and left the subview frames in an inconsistent state:

6/26/08 09:07:56 Safari[60303] The outer edges of the subview frames are supposed to line up with the split view's bounds' edges. NSSplitView is working around the problem, perhaps at the cost of more redrawing. (This message is only logged once per NSSplitView.)