It is really important to do your research before you ever update your iPhone 3g, well that is especially if you are unlocking your iPhone 3g or ever just jail breaking it.
Now you may be scratching your head and asking why? It very simple let’s take the last few apple iphone 3g updates for example.
1)2.1 -2.2 now I am sure you all know about the iPhone 3g 2.2 update … this is the one where your turbo sim stopped unlocking your iPhone … we all loved that didn’t we … *(I Sure didn’t) that is when I had to put my iPhone 3g aside for almost a month, and all my friends were asking me David where is the iPhone you spent $700 on eBay? … Dude it doesn’t work for now ,,, and I had to explain all about the iPhone 3g updates and jail breaking and unlocking the iPhone 3g and all… as I am sure you can imagine it was no fun. Then in new years the dev team came out with the soft Yellow Sn0w unlock the … witch at the end everyone had to update there iPhone 3g to the 2.2 with the Modem firmware 02.28.00 to every make the soft unlock work.
2)2.2 -2.2.1 Not long ago apple came out with the 2.2.1 iPhone 3g update with the Modem firmware 02.30.03 , Now history repeats its self. If you didn’t read all the warning online then you made the update to 2.2.1 with 02.30.03 firmware witch cants be unlocked with a soft unlock but only with a turbo sim.