After reset , iPhone won't turn on. Need to find out firmware!

[tuna9720]

Guys. I had a jailbroken iPhone 3G with ATT of course but I've sent this phone to my cousin who lives in europe. Before I've sent I did a full reset by going to settings and where ever is the reset button . And I havent turned it on before I sent the iPhone.

Now what my cousin says is , in order to turn it on they have to know what the last updated firmware was. Because it does not recognize their local sim card. And it can't be turned on unless they jailbreak it . But what they say is , if they try to jb a wrong firmware it might not work again. Is that true? And if so , is there a way to know the last firmware? Or any other idea to turn it on or to jb it without causing any problem?

Any experience on that?

Ps: When they plug it in to iTunes it shows this

http://www.theiphoneblog.com/images/stories/2009/01/iphone_recovery_mode-266x400.jpg

 

[abijnk]

The latest firmware is unlocked already, so just have them restore the phone to 3.0 in iTunes and then use redsn0w to jailbreak and ultrasn0w to unlock.

 

[tuna9720]

The latest firmware is unlocked already, so just have them restore the phone to 3.0 in iTunes and then use redsn0w to jailbreak and ultrasn0w to unlock.

So does it cause a problem if they restore it to a different firmware other than the one before reset?

As I said earlier , they think that if they restore a wrong firmware it will never turn on again