JAVA AES keylength exception

I am developing a JAVA application that must encrypt its data. On my development machine, I can use a 256 bit key with no problem. A test machine throws an exception complaining about an illegal key length. The test machine is using JRE 1.6u21. Does anyone know where I can get a version of the JRE that supports the 256 bit keys?

What is the exact exception text?