Karth Vahlnar wrote:
Perhaps they did not have the incompatible bit of software that caused a conflict with the 3.1 update resulting in loss of VMM. The fact that not all iPhones were affected does not by itself negate the possibility that the loss of VMM is nevertheless still related to application of the 3.1 update.
It may be "related" to the update, but does not appear to be a 3.1 bug. When you say "not all..." your glossing over the fact that this has happened in an extremely minute fraction of iPhones. The great majority posting in this thread (and not very many at that) had installed a tethering hack. The remaining few positing here who claim that their phones have never had unauthorized alteration, even if they represent only 1% of those actually affected, still represent <0.001% of iPhones upgraded to 3.1.
VVM is a feature controlled by the cell carrier, and is installed in the phone via the carrier profile file. If VVM is lost, it's undoubtedly due to curruption of that file, or a local carrier issue.