[bug?] df and du -s output inconsistent?

[Olaf Meeuwissen <olaf@epkowa.co.jp>]

Hi all,

Yesterday I got an I/O error telling me that the /home file system was
full.  Bummer!  Checked with df and sure 0% free in /home.  Looked all
over /home to find disk hogs and removed a really big .xsession-errors
file---still have to find out what caused that---and thought all would
be well again.  Unfortunately, nope!  I'v since removed some more gunk
and can work again, but ...

There is something funny about the output of df and du -s.  Just take
a look at the typescript below:

  bash-2.03$ df /home
  Filesystem           1k-blocks      Used Available Use% Mounted on
  /dev/hda7              2058900   1652232    300239  85% /home
  bash-2.03$ du -s /home
  661643	/home

According to df about 1.6Gb of the /home partition are used whereas du
-s says it about 1Gb less.  Who's wrong?  Or am I missing something?

Thanks in advance.
-- 
Olaf Meeuwissen       Epson Kowa Corporation, Research and Development