Comment 3 for bug 720924

With Natty release in kvm with usb flash attached:

 - with usb flash containing an iso image (copied with dd) usb-creator-gtk offers only the option to erase the flash and fails to do so, gparted fails to repartition
 - repartitioning with cfdisk creates a partition table that gparted understands. Created a single fat32 partition over the whole device. usb-creator-gtk offers only the option to erase device which again fails.
 - created a fat32 filesystem over the whole device (superfloppy) usb-creator-gtk offers only the option to erase disk which fails

The error gparted reports in terminal:

Input/output error during write on /dev/sda
Error fsyncing/closing /dev/sda: Input/output error

As the only error in GUI is reported when creating the partition table I guess this is the cause.

Interestingly, the partition table is created. cfdisk does not have this issue while creating a partition table.

Another interesting thing is that rebooting with the flash disk already partitioned and formatted fixes the issue.
usb-creator-gtk offers the option to make a startup disk then.