LiveUSB Creator help for F18 install

I am trying to use LiveUSB Creator to install F 18 Desktop. Got the following:
Fedora-18-i686-Live-Desktop.iso selected
Verifying filesystem...
Verifying ISO MD5 checksum
ISO MD5 checksum passed
Extracting live image to USB device...
Wrote to device at 4 MB/sec
Creating 2093MB persistent overlay (I did this could it be the problem?.)
Setting up OLPC boot file...
Installing bootloader...
LiveUSB creation failed!