Logged In: YES 
user_id=752496

This is a documentation bug; something the user should be
"warned" about. 

This caught me once, and two different persons asked about
this in #python, so maybe we should put something like the
following in the recv() docs.

"""
For best match with hardware and network realities, the
value of "buffer" should be a relatively small power of 2,
for example, 4096.
"""

If you think the wording is right, just assign the bug to
me, I'll take care of it.