Comment 2 for bug 210620

Reproducing:

Running os-prober several times on a live-cd system may produce error messages. This is less time consuming than running ubiquity to reproduce the errors, but I verified the success of the suggested patches below by running both os-prober and ubiquity (up to the verification screen).

Since this bug is prompted by asynchronous processes results can be haphazard.

Circumvention:

Mount all partitions to the live-cd system using

sudo mkdir /media/hdxx
sudo mount /dev/hdxx /media/hdxx

(using using Applications/Accessories/Terminal)

the target partitions should probably be unmounted with the sudo umount command before proceeding with formatting and installation. I haven't tried going on beyond the verification screen.

or more easily and perhaps more safely:

Bring up Home Folder from the Places menu
Select Edit->Preferences
Select the Media Tab
Check the second last selection at the bottom: "Never prompt or start programs on media insertion"

Please let me know if I can help with further information or otherwise. Logs and suggested patches follow.