  We report on the analysis of archival ASCA, ROSAT and BeppoSAX data of PSR
B1055-52, PSR B0656+14 and Geminga, performed in order to investigate the
reality of the putative ~10-20 arcmin wide X-ray pulsar-wind nebulae recently
proposed to exist around these pulsars.
  In all these cases, the ROSAT and/or BeppoSAX data show that the diffuse and
clumpy X-ray nebulae found by ASCA can be resolved in the contribution of
unidentified point sources, unlikely related to the pulsars.
