Created a level 85 shaman then bought dual wield then put one of the specs as enh and one of the specs as resto.
Once’d I’d activated resto I then reactivated enh and didn’t re-learn the passive ability dual wield so couldn’t DW weapons.
Deleted and re-created a shaman and it learns passive DW when I spec enh but as soon as I purchase dual spec and active spec 2 (usually resto) I lose DW as expected. When I active enh I don’t re-learn dual wield passive.