Reported by a user on IRC. I could reproduce the issue using the iso in $summary.
I have also this problem. I'm running it from Virtualbox 4.1 on Windows 7 host.
same problem with install-amd64-minimal-20110721.iso. install-amd64-minimal-20110714.iso worked just fine.
I've updated catalyst in the box that creates the amd6 / x86 install cds, so this shouldn't happen again. Thanks to Alex, I've moved the affected versions away from the mirrors. Feel free to reopen if you hit this issue again.
The same problem with http://distfiles.gentoo.org/releases/x86/autobuilds/current-iso/install-x86-minimal-20130528.iso
Same problem with install-x86-minimal-20130528.iso Dell Latitude D830
Please don't bump 2-year old bugs. File a new one.