apt-get upgrade size mismatch question

["Jason Holland" <jphollan@earthlink.net>]

hello all,
  i'm having a small problem with apt-get and was wondering if anyone can
help out.  i'm running woody by the way.  everyday i run apt-get update and
apt-get upgrade, but i always get these errors when performing the upgrade.

Failed to fetch
ftp://ftp.twoguys.org/debian/dists/woody/main/binary-i386/admin/devfsd_1.3.1
0-1.deb
  Size mismatch
Failed to fetch
ftp://ftp.twoguys.org/debian/dists/woody/main/binary-i386/libs/libgmp2_2.0.2
-8.deb
  Size mismatch
Failed to fetch


i usually have to go to /var/cache/apt...  to manually install the debs,
which is a real pain.  anyone know why it fails to install because of a size
mismatch??  a workaround for this would be nice.  thanks!!

Jason