My wife has a factory unlocked 3GS with a T-Mobile SIM in it. It has worked so-so for a year, and then in the last couple of months things had improved she can occasionally pick up 3G and MMS is finally working correctly. Just today, though, she noticed that she didn't see the new voicemail indicator even though she knew someone had left her a message. Which lead her to discover that Visual Voicemail now shows up when she taps the Voicemail icon in the phone app. Previously, that button just called into her VM, exactly the same as pressing and holding "1" on the dialer. But, Visual Voicemail doesn't actually work. In testing tonight, I was able to get the old behavior back briefly after restarting the phone the Voicemail button called voicemail rather than showing VVM, and when I left a test message she momentarily got the new message badge. But within a second or two the badge disappeared and phantom VVM was back. This seemed to happen spontaneously, sometime in the last week. My assumption is it has something to do with T-Mobile refarming or changes to the carrier settings, but I don't know how I can fix it for her. The phantom VVM itself is annoying but not a huge deal; losing new-VM badging is a big problem, though.