Jailbreaking problems with my 2 gen?

I have an iPod touch 2 gen. It is running on 4.2.1 and I intended on jailbreaking it. I downloaded gp rc6 and followed all the steps and making sure I did nothing wrong. At the point of jailbreaking, my iPod white screened, but never started filling my screen with code. It stays white screened and then it says jailbreak failed so I unplug and hard reboot. I have also tried this with gp rc5_b2 and same problem occurs. Any suggestions on how to overcome this?