I'm running debian 7 stable release with unetbootin 575-1
If I run 'sudo unetbootin' and select my ISO image (boot-rescue-32bit.iso) and select my newly formatted USB drive click ok, then unetbootin gets stuck on Extracting and Copying Files at 0%.
I've tried the latest unetbootin 608 version as well, same problem.
I've also tried a different ISO, still no joy. Both of the ISO files I know work as I've burnt them to CD and booted them on a computer.
I've also tried a different USB flash drive and a different USB slot (on-board instead of through a USB hub)