I get that you need SHSH blobs to down grade but this is a brand new phone never taken out of the box. Why would it not let me upgrade to 4.3.3?

Hi I hope some of you have got the answer I need. Last week I jailbroke my 3GS that was on 4.3.2 and all went well, I back up yesterday on itunes and then got my new iphone 4. when I tried to restore my backup from my 3gs onto my new iphone 4 it said I needed to update the new iphone to 4.3.3...