I grabbed knoppix from the official BT Tracker here as soon as i knew it was up, (probably within an hour of going on the tracker).

Now, here is what i did when i got the file:
matt@srv1:~/software/linux/knoppix/3.4$ ls
KNOPPIX-CHANGELOG.txt* KNOPPIX_V3.4-2004-05-04-EN.iso.md5.asc*
KNOPPIX_V3.4-2004-05-04-EN.iso* knoppix-cheatcodes.txt*
KNOPPIX_V3.4-2004-05-04-EN.iso.md5* packages.txt*
matt@srv1:~/software/linux/knoppix/3.4$ cat KNOPPIX_V3.4-2004-05-04-EN.iso.md5
49a62cdac7a3afcee0d2d47ea17daa6f *KNOPPIX_V3.4-2004-05-04-EN.iso
matt@srv1:~/software/linux/knoppix/3.4$ md5sum -c KNOPPIX_V3.4-2004-05-04-EN.iso.md5
KNOPPIX_V3.4-2004-05-04-EN.iso: OK
matt@srv1:~/software/linux/knoppix/3.4$

Now, on the FTP servers are different MD5 files, so whats going on, has their been a change to knoppix since it went on the tracker, that has only been added to the ftp servers?