10-26-2011 11:53:13 AM
I have on repeated occasions failed to receive a timely notice on my phone that I have VM waiting. The latest ocurrence was a VM dated 6:01 PM 10/25; as of 11:30 AM on 10/26 there was no VM indication on my phone.
10-30-2011 02:27:09 AM
VM indicator is triggered by a specially formatted text message sent by the carrier. If you receive the VM when your phone is going in and out of service it may take a long time (I've received notifications as late as two days) for the VM indicator to come up.