I did the check with the cheatcode but the screen turned black again.
When I do the md5 with the toast442.org md5 gui program the numbers doesn't match at all:

7a64bbcd3a02b376d722815a232cec22 this is the actual checksum

45378e8ef81b27 and so on is the file checksum.

The iso and the md5 file do have the same filenames:
KNOPPIX_V3.1-2003-01-20-EN