Doublewide is no longer needed. According to the Blizz patch notes, they added that function into the default UI. Try disabling it and see if stuff is still screwy.
From the 3.2 Patch notes:
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The quest log is now double-paned for more easily viewing quest information. The list of all quests a player has will show in one pane, while the quest details of any highlighted quest will display in the next.
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