As I noted earlier, the posted .jar by cooper worked just fine for me and has ran all night with no errors. However, I placed the same jar file on my other computer and I get the same error as mentioned above "unable to rip MP3 String index out of range: -1"
I know that both systems are running the exact same java/firefox/and pandora.jar.
I even copy and pasted the working folder to the non-working computer to no avail.