Is there something wrong with T-Mobile's voicemail system?

A fair number of people have been complaining about weird things going wrong with T-Mobile's voicemail system, like outgoing messages being replaced with other people's outgoing messages, getting voicemails meant for other people, calls going straight to voicemail, then ringing, then going back to voicemail, etc.
It's hard to tell how widespread this might be or whether it's just the usual network troubles (there's always bound to be someone experiencing problems on a network as large as T-Mobile's), and when we called T-Mobile's PR rep last night they told us that they hadn't heard of anything unusual going on.