Double mindedness, distortion of our mind, distraction of our mind, disbelief.  Dubidha takes us away from the core of GurBani.  Dubidha means duality.  Duality means that there is something else other than God.  When these thoughts, that there is something other than God, take over our mind it side tracks us from the divine truth.  The worst thing we can do is to doubt Gur Mat.  That is why we are carried away by the Sansarik Mat – worldly wisdom, or our own Mat – self wisdom or Dur Mat – which is the bad wisdom.  Any negative force that takes us away from the divine truth is Dur Mat.  As long as we are wandering in the wilderness of Panj Doots and desires we are operating under the Dur Mat.