Within the noncollinear local spin-density approximation, we have studied the ground state structure of a parabolically confined quantum wire submitted to an in-plane magnetic field, including both Rashba and Dresselhaus spin-orbit interactions. We have explored a wide range of linear electronic densities in the weak(strong) coupling regimes that appear when the ratio of spin-orbit to confining energy is small(large). These results are used to obtain the conductance of the wire. In the strong coupling limit, the interplay between the applied magnetic field -irrespective of the in-plane direction, the exchange-correlation and the spin-orbit energy, produces anomalous plateaus in the conductance vs. linear density plots that otherwise are absent, or washes out plateaus that appear when the exchange-correlation energy is not taken into account.