http://docs.python.org/tut/node5.html states, as an example, round(_, 2)
should round to the second decimal place.  makes sense.  when i
attempted it with different numbers, round() returned what looks like a
binary-coded decimal error (see the jpg enclosed), and did not return
just two digits, but 15 digits.  the same error was produced for
round(_, 3).  when the number was changed to 1 digit, the return result
rounded from another direction.

i'd guess this isn't a feature :)