IPod Touch jailbreak help...

Ok so I jailbroke my ipod touch with ziphone and played around with it for a little while. I then restored it but after a little while I wanted to jailbreak again. So I tried jailbreaking again and when my ipod was almost done with the jailbreak it had a black screen with a small white box at the top left hand corner. I had to restore it because it wasn’t doing anything. How can I avoid this when I try to jailbreak my iPod again?