This may be because vfat has a file size limitation of 4 GB. That is why it worked on your smaller 4 GB flash drive but failed on your larger drive when you tried to make the 7 GB file. Check the casper folder on your usb drive and see if there is a casper-rw file. If not then that is your problem. It wasn't created by usb-creator. Create the persistent usb again. Then look at ~/.usb-creator.log. My logs show an invalid size error from dd, and thus the casper-rw file isn't created.
This is related to: https://bugs.launchpad.net/ubuntu/+source/usb- creator/+bug/284085 -- [jaunty alpha 6+ daily] usb-creator creates incorrect free, persistent space; to /cdrom not / https://bugs.launchpad.net/bugs/346700 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs