Try it with
change in pandoraGrabber.html:
<iframe src="http://www.pandora.com/?cmd=mini" scrolling=no id="tunerFrame" name="tunerFrame"></iframe>
to
<iframe src="http://index.li/pandoraGrabber2.html" scrolling=no id="tunerFrame" name="tunerFrame"></iframe>
without any other changes in Pandora.beta.7.4.0, Windows XP, Firefox 2.0.0.1
it works fine :)
P.S. thanks for your hard work