This goes back to my last post about the speakerphone hiss. To recap, I did something at some point on my phone which greatly improved the hiss. However I did not ever do it on my wife's phone and am trying to remember what the hell I did so that I can fix her hiss.

Well I think I figures it out. I updated my phone to 1.21 as per instrustions here:
But never upgraded wifey's. After retracing my steps this is the best guess that I have been able to figure out. So... my questions are: what risk is there when downgrading a phone to a earlier version. Secondly, does anyone have a copy of this Singapore leaked version that is in this thread? I think that the answer to the hiss issue for unlocked GSM may lie in this update.