Can't unmount the usb drive, won't continue

I have an 8GB usb flash drive that was formatted to fat32. I put it in the usb port, booted off the latest Ubuntu 8.10 disk and then downloaded liveusb after I had it booted and then ran the program from a terminal window: sudo liveusb

I kept getting an error that there was no space left, error in mtab when it tried to unmount the existing partitions and the setup would not continue. I had to remove all the partitions from the usb drive manually, then reboot, then go through the whole process again. If I choose persistent, then it can't unmount the home-rw drive. So, I am now waiting (over an hour now) for it to finish creating a plain live boot without persistence.

I had read somewhere that the automount issue had been fixed, but for some reason I couldn't get my partitions unmounted even manually as sudo.