So I followed these directions to install Hardy Heron as persistent on a 4 GB flash drive and it almost worked.

Almost.

When I boot up it asks me if I want to boot persistent, non-persistent, install, etc. If I choose non-persistent, it boots fine. Installs nice and quick too. But whenever I boot into persistent mode, I get an error. It will do the Ubuntu load screen where it has the orange bar moving back and forth, but just when it gets to the actual load part, where the bar gets progressively bigger, it gives me a buffer I/O error. I'm kind of confused... why does it boot non-persistent just fine, but persistent gives me an error?

Thanks!