I own an İphone 2g. ( I need SIM unlock)

I successfully restored it via itunes.

I tried both redsn0w version 0.71 and 0.72.

here is my first question,

should I check the unlock button? (I know it makes non sense but I read I shouldn't do it)

second,

phone got stuck on the screen written "Downloading jailbreak data".
and the is no white loading circle under it.
I don't know what to do.

Anyone help?

if you restored sucessfully via itunes, switch off the phone and start redsn0w as administrator, if you are on Vista (sometimes it get stuck just where you mentioned). make sure to use the same ispw, which will be recognized by redsn0w. Check the cydia and unlock box. Then it should work perfectly, but take care, all phone numbers and sms disappear. The rest of data will be sincronized perfectly.