Using a slightly modified formalism of the equations of smoothed particle magnetohydrodynamics, we have performed simulations of the collapse of magnetised molecular cloud cores to form protostars and protostellar outflows. This more stable formalism allows us to both utilise smaller (atio of 3) and weaker (mass-to-flux ratios of 10 and 20) magnetic fields. We find that the nature of the outflows produced is strongly dependent on both the angle between the field and rotation axis and the mass-to-flux ratio: most strikingly, with a field at 90 degrees to the rotation axis and a mass-to-flux ratio of 20, the core fragments into a binary. These results place strong constraints on the nature of first hydrostatic core outflows and the field geometries that create them.