Comment 5 for bug 352766

Usb-creator is just a script. It is quite easy to just apply the patch from https://bugs.launchpad.net/ubuntu/+source/usb-creator/+bug/321544 to the text file. If you don't feel comfortable doing that. Then you can manually just find and change 2 lines. It is quite easy. Here are the relevant lines from the patch. Just find them in the usb-creator script and replace the '-' version with the '+' version.

- popen(['dd', 'if=/dev/zero', 'bs=1', 'of=%s/casper-rw' % target, 'count=%s' % persist])
+ popen(['dd', 'if=/dev/zero', 'bs=1024', 'of=%s/casper-rw' % target, 'count=%s' % (persist/1024)])

- persist = arg
+ persist = int(arg)

After this you can run usb-creator like normal and you will be fine with any persistence file < 4GB. This is what I did and I everything worked great for me.