installation CD checksum failure

[Haines Brown]

I purchased a ubuntu 6.6 CD and did an install. However, it hung at:
Installing system; copying files, 34% 2:54 remaining.

I tried again, and then again with the CDROM checksum test, which
ended: Check finished: 1 checksums failed. The checksum failure seems
to be with ./caspar/filesystem/squashfs.

I inspected the CD and dusted it carefully.

Is it likely that I was sold a flawed CD? This squashfs is enormous in
size, and I suppose is holds all the installation files archived. Any
approaches to this problem other than reordering the CD? 
-- 
 
       Haines Brown
         KB1GRM
         ET1(SS) U.S.S. Irex 482