An update T-Mobile apparently implemented in the past 2 days seems to be causing major problems for voicemail on unlocked iPhones. AFAIK, this issue only affects iPhones on T-Mobile in the United States (where they have presumably been unlocked for this purpose). The issue causes voicemail alerts to not function properly -- instead of causing the voicemail red ball indicator to appear on the Phone icon in the springboard, instead, they generate spurious, blank SMS entries (typically no sender or contents, I think some of them have a lone "@" in them). When one checks voicemail, the fake SMS entries also get created when it tries to clear out the new voicemail indicator. I found this out, sadly, because I rebooted my iPhone this morning -- it didn't happen until then (but I also didn't receive a voicemail I think yesterday or today). Here are some references: http://www.howardforums.com/showthread.php?p=12518412#post12518412 http://www.hackint0sh.org/forum/f127/71287.htm#post406903 I'm still poring through them, but there doesn't seem to be a good fix right now. EDIT: Two things are suggested as fixes or workarounds: - Some users report that getting a new SIM from T-Mobile solved the problem, but others reported that they did the same and it did not solve the problem - Some users are using Youmail as an alternative. I'm going to give this a try, since people say Youmail actually does some fun stuff. Here's some info. This seems to be at least a temporary solution, although if one has the problem that the voicemail indicator red ball is shown on boot, there doesn't seem to be a way to get rid of it, as calling their voicemail service doesn't seem to get rid of it.