[h-e-w] dired formating inconsistent

[Sarir Khamsi]

After using Emacs 21.3.50.1 for a bit, I've noticed that the output of
dired does not seem to be consistent: sometimes the listing of the
filenames does not align correctly. Unfortunately, I can't seem to
determine what conditions cause this (eg. certain directories,
filenames, phase of the moon, etc). Has anyone seen this and have a
solution? Thanks.

Sarir