It could probably be added as a new section to this FAQ, as its pretty small right now.Should there be a sticky FAQ on diagnosing these common problems and possible solutions? At least one user successfully "fixed" a DSTT that had bad contacts by bending it slightly (although I would reserve that solution as a last resort). Others have had success with the less drastic approach of placing a piece of cardboard or paper inside the port before inserting the cart, helping it to make contact with the NDS.
However, I don't think at this current time we have enough facts to come to a definitive conclusion on what causes/solves the contact and incompatibility issues. Reports seem to be pretty varied.