Unlocked 3GS - Vodaphone - can I update to iOS4

[mac2thefuture]

I have an unlocked 3GS which was done vis iphoneunlockuk and is currently using a vodaphone sim. Version 3.1.2 (7D11) and i'm using iTunes 9.2.

It seems that i'd have to pay approx £15.00 to use iphoneunlockuk's pakage to update to iOS 4.

A couple od questions -

1. Once a phone is unlocked, (as it currently is) does it stay unlocked? i.e Can I just update my software to iOS 4 free via iTunes?
2. If not, is it done easily free of charge via the internet?

Thanks

 

[LaeeqB]

Upgrading to os4 will get rid of your jailbreak and unlock. But you can easily jailbreak and unlock for free using jailbreakme.com and installing ultrasn0w from cydia. Also, if you don't have any sim of the official iPhone carrier in the UK or wherever it is you live, then you may have problems with activation after upgrading.