Aside from the fact that it helps unrelated people aid you in diagnosing
the problem, there's another, more practical reason to do it:
When you do, problems you're having will sometimes "magically" disappear,
because someone who a) is in a position to fix it, but b) is not in a position
to *talk about it* will see the report, do a facepalm, and twist the proper
knob to make it go away.
While this isn't as optimal in the global sense as a full dialogue on the
problem would be, it's a helluva lot better than "it still doesn't work,
a week later". And the shorter the thread, the higher the odds this might
happen. "One posting" is optimal. 
Just a thought.
Cheers,
-- jr 'Happy Chriskwanzukkah, and a Cool Yule' a