Jailbreak Errors

[Dcacch]

I did all the steps needed and did the software.. and then im going into DFU mode and i do all the steps to that and then itunes comes up and has some error i think its 21 or 2001, anyways then it says im sucesfully in? well then i quit itunes and go back in and try to restore and it doesnt show my ipod. so then i unplug my ipod and start it up and i plug it back into itunes and its in recovery mode and i have to reinstall everything.. what am i doing wrong..
i read a post saying if you have new software it keeps you from getting into dfu mode, i have the old/new macbook pro, running 10.5.6 Plese help!

 

[Dcacch]

and can anyone tell me how to restor emy iphone back to stock incase anything goes wrong or i dont like it jailbroken.

 

[mattplex]

iTunes has a restore option in the iPhone section.