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A background component, variable in magnitude and related primarily to the particle background, became apparent in the summer of 1991. This component consists of very low pulse height after-pulses which follow very shortly after a ``precursor'' event. Some of these after-pulses can be removed by rejecting all events occurring within 0.35 ms after another event, which eliminates all such events associated with telemetered X-ray events. Unfortunately, except near a bright source, most of the precursor events are particle background events which have been vetoed by the on-board electronics and are therefore not telemetered to the ground, which makes selecting against their after-pulses impossible.