For short-duration GRBs that are promptly (within ~ 100 s) followed up by the X-Ray Telescope (XRT) on Swift, ~ 80% have detectable X-ray emission.  While this is a relatively large fraction, it is noticeably smaller than the fraction of long-duration GRBs, for which nearly every promptly followed burst is detected in X-rays.  In fact the early X-ray emission from some short GRBs fades extremely rapidly, becoming undetectable by the XRT within ~ 1000 s.  It is not clear if the X-ray emission in this case is bona fide afterglow emission, or simply the high-latitude tail of the prompt gamma-rays rays.