[Hampshire] Baffled by df/du

Just done a clean minimum install of Debian Etch under VMWare 
Workstation 5.5 and I find df reporting:
Filesystem           1K-blocks     Used Available  Use% Mounted on
/dev/hda1              1359816   287656  1992884    23% /
udev                     10248       56    10184     1% /dev
devshm                  128588        0   128588     0% /dev/shm
/dev/hda6              2601116    69516  2399469     3% /home

du -s /home reports
40 /home


du's 40 used blocks != 69516 Used in df
I know there is a simple explanation, but what is it?