I'm having the same issue with Ubuntu 12.04 LTS.
I've tried with a completely clean install with the only non-default package being ssh server, got these exact errors.
After trying that twice, I also tried to do the install with doing the mysql install and setting the password BEFORE the install, and that also failed with the exact same issue.
I confirmed that the password in the config file is the password I expected. I'll try to add this lines in the backend.sh shortly and report back.
Edit---
Doing the Fresh/Clean install now with the modified .sh, Just finished doing the ubuntu 12.04 reinstall. I noticed that (and this was the same way on the previous installs) that the dialog boxes seem to have some amount of corruption in them (attached file), but the config file seems to have the proper data in it.