I have telco-provided voice mail on a land-line. I like it because its easy to retrieve messages from anywhere and, unlike answering machines, it allows callers to leave a message instead of getting a busy signal if I'm on the phone when they call.
I think its overpriced, but still deem it worth having. However, for the last week I've had lots of trouble with the message-waiting indicator. (You hear a stutter in the dial tone when you pick up the phone, this indicates a message is waiting.) The time between a message being left and the indicator getting set has always been too long, in my opinion, but now it was stopped working entirely.
I called AT&T this morning and learned the following:
When you are finished listening to your voice mail, always press * (star) repeatedly until you hear the prompt asking you to enter a mail box number. If you simply hang up, your mail box is in a bad state and the message indicator will not function correctly.
Unfortunately, this isn't documented in the voice mail instructions that I received when I signed up for the service. And while "logging out" isn't that big of deal, its quite bad that failing to do so can disrupt a major feature of the product. Apparently, they have no plans to fix this bug. So, take note.