Livecd.iso has checksum error

Hi, I am trying uck-1.1 with Dapper. I've found that there is always checksum error if I select "Check CD for defects" options with the livecd.iso, running under Qemu. It reported "Check finished, 3 checksums failed".

I did not make any changes to the package, just run the customize-cd-gui script, with ubuntu-6.06-desktop-i386.iso as the source. I have checked the md5sum of the iso and it is confirmed correct.

Has anyone come across with such problem? Thanks in advance.