Remove blackra1n jailbreak from ipod touch 3.1.2?

[cturco]

I wanted to remove my blackra1n jailbreak from my ipod touch 3.1.2, so i clicked reset on itunes to return it to the store setting. When i did though, a popup came up saying that my device was broken and could not be reset to the store setting. I was able to quickly blackra1n my ipod back but i really want to remove it so that i can get the new update. Help??