Hmm, I suppose you installed unetbootin from the repos. Ubuntu still has version 608 in there from 2 years ago. Things have changed.
Go to Sourceforge to download a recent binary (version 647 is good for Bodhi) from there for your system, I think you will need the linux64 if memory serves me well.
Execute this command:
sudo cp /usr/bin/unetbootin /usr/bin/unetbootin-old
so you have the earlier version still available.
Now save the new bin file to this place:
sudo cp /path/to/file/unetbootin-linux64-647.bin /usr/bin/unetbootin
Replace path/to/file with your path
You need to make the binfile executable and readable for anyone first.
Use the terminal to start unetbootin, the menu entry uses a command with references to QT and refuses to boot.
NB1: Unetbootin seems no longer to format the flashdrives but starts copying right away, so you format as FAT32 before using it.
NB2: When unetbootin when creating the bootloader asks to overwrite existing files related to isolinux and such answer NO. It must use the existing files from the ISO and not its own version.
Made a flashdrive successfully but I've not yet tested the flashdrive on a real machine.