I am still downloading - on a slow connection - and so haven't tried yet.

That said i had some problems with startup disk creator the other night - trying to create a 12.04 live USB to install on a family member's machine, while running 12.10. A bit of a search revealed this: https://bugs.launchpad.net/ubuntu/+s...r/+bug/1068473

It seems a bit bizarre that this bug didn't get more attention.

Try using unetbootin.

Please report your findings.