Computing sha1sum of dvd iso

[JD]

  Dear All,
After I downloaded the F12 DVD iso and the CHECKSUM file,
I executed
sha1sum Fedora-12-ppc-DVD.iso
Thevalus that comes out is the not the same as what
I see in the CHECKSUM file. Not only that, it is of a much
shorter length. To wit:

$ grep DVD.iso Fedora-12-ppc-CHECKSUM
800ef4f121e178dcc9c8dc128825021949abe0d6d029f36cd47e39a4033c3aaa     
*Fedora-12-ppc-DVD.iso


$ sha1sum Fedora-12-ppc-DVD.iso
548e1b544c400d39be4fbd080080424e2b5c7674      Fedora-12-ppc-DVD.iso

So why the discrepancy - or by what metod is the sha1 signature of the 
iso computed and distributed in the
Fedora-12-ppc-CHECKSUM  file?