I have the same problem as well. I recently changed my root password from the default 'rootme' before reinstalling this applet and changed the password in the shell script as well. When I tried using the hacky brightness bar, it does not work with the new password. But I tried returning the root password to the default 'rootme' and which, well, worked of course.

Is there some way that I can use my new root password for this applet? I have tried reinstalling the applet and rebooting as advised in this post, but to no avail.

cheers.