I ran into this bug trying to make a Ubuntu 10.04 USB stick from the 10.04 iso on a running 10.04 system. My workaround was to run the program as superuser (gksu usb-creator-gtk). The iso was not moved from the download directory (was autodetected), and I didn't have to do anything to /sdb. I did waste a lot of time, though.
As it seems that the bug is still there, and the workaround doesn't work in 11.04, perhaps the general instructions here ( http://www.ubuntu.com/download/ubuntu/download ) need to be changed.
I ran into this bug trying to make a Ubuntu 10.04 USB stick from the 10.04 iso on a running 10.04 system. My workaround was to run the program as superuser (gksu usb-creator-gtk). The iso was not moved from the download directory (was autodetected), and I didn't have to do anything to /sdb. I did waste a lot of time, though.
As it seems that the bug is still there, and the workaround doesn't work in 11.04, perhaps the general instructions here ( http:// www.ubuntu. com/download/ ubuntu/ download ) need to be changed.