sha1sum output: what does it mean?

Tue Jun 14 10:06:06 UTC 2005

I've got the following output after running sha1sum on my recently
downloaded (BitTorrent) FC4-x86_64-DVD.iso:

FC4-x86_64-DVD.iso: OK
sha1sum: FC4-x86_64-SRPMS-disc1.iso: No such file or directory
FC4-x86_64-SRPMS-disc1.iso: FAILED open or read
sha1sum: FC4-x86_64-SRPMS-disc2.iso: No such file or directory
FC4-x86_64-SRPMS-disc2.iso: FAILED open or read
sha1sum: FC4-x86_64-SRPMS-disc3.iso: No such file or directory
FC4-x86_64-SRPMS-disc3.iso: FAILED open or read
sha1sum: FC4-x86_64-SRPMS-disc4.iso: No such file or directory
FC4-x86_64-SRPMS-disc4.iso: FAILED open or read
sha1sum: FC4-x86_64-disc1.iso: No such file or directory
FC4-x86_64-disc1.iso: FAILED open or read
sha1sum: FC4-x86_64-disc2.iso: No such file or directory
FC4-x86_64-disc2.iso: FAILED open or read
sha1sum: FC4-x86_64-disc3.iso: No such file or directory
FC4-x86_64-disc3.iso: FAILED open or read
sha1sum: FC4-x86_64-disc4.iso: No such file or directory
FC4-x86_64-disc4.iso: FAILED open or read
sha1sum: FC4-x86_64-disc5.iso: No such file or directory
FC4-x86_64-disc5.iso: FAILED open or read
sha1sum: FC4-x86_64-rescuecd.iso: No such file or directory
FC4-x86_64-rescuecd.iso: FAILED open or read
sha1sum: WARNING: 10 of 11 listed files could not be read

What does it mean? 
Should I download the file again because of the missing files?

Leopoldo Olmos