iPhone restarts frequently whilst tethering via. USB When tethering via. USB on my iPhone 4 (4.2.1) with my MacBook Pro (10.6.5) I frequently encounter:


my iPhone freezes with either a black screen (hard reset) or a frozen screen (hard reset)
my iPhone restarts itself and reestablishes its internet connection


I can go for an hour or two without a problem, or it might happen after a few seconds. There seems to be a correlation between the amount of data I'm pulling and the frequency of the crash. 

I'm using Vodafone New Zealand's 3G network. Tethering is a free feature (using our existing data) here, and we don't need to do anything to enable it. Tethering worked a charm on my old iPhone 3G. 

The problem seems to be a common one. 

Has anyone encountered this problem and found a fix, or, has anyone called Apple about it to submit a bug report?
Try restoring/updating your phone to the newest firmware from apple. (4.3)