Comment 122 for bug 1080701

Happens for me with both beta 2 and today's daily, on 2 out of 3 machines tested.
All three systems are dual-boot and have plain old pc style extended partition tables.

comment 88 suggested that turning off swap might work around the problem, but it didn't seem to for me :-(

comments 88 and 121 suggested that mounting a partition might work around the problem. I can confirm this;
on the first machine I tried, doing ctl-alt-f1 and 'sudo mkdir /media/foo; sudo mount /dev/sda5 /media/foo',
then clicking Continue brought up a warning box
  "Unmount partitions that are in use?"
Clicking 'No' on that dialog let me get to the Installation type dialog, and installation worked fine from there. Yay!

Given that this affected 2 out of my 3 machines, this seems like a release blocker; not fixing it before release
will probably result in widespread knowledge of this workaround and a few hits to Ubuntu's reputation.

I'm happy to retest if there's progress.