Post any defects you find in the released or beta versions of the ImageMagick software here. Include the ImageMagick version, OS, and any command-line required to reproduce the problem. Got a patch for a bug? Post it here.
I have no idea what the problem is but the lack of any others saying they have the problem I would guess points to your setup.
Is there a problem with the random files - post a link to one of the bad ones for others to test.
Have you upgraded Debian
Have you upgrade Imagemagick
What version of Imagemagick are you using
Searching Google for "Socket operation on non-socket" on Debian error returns some results and there may be something useful there.