My Mom has premier, and we have all calls that aren't in her contact list dumped to voice mail. This system works pretty well, but she complains that her phone will ring once at about 5:00 a.m. and wake her up. When I check her call logs, there's nothing showing but white listed calls at normal times. There's never anything on the caller ID log on her phone, but a single ring wouldn't be long enough to log it.
In the myooma the Preferences on the call Call Blocking screen the slider on the left is set to "Custom" and all of the green check boxes are checked. The last one for "Block all numbers in my contacts and" has "Send to Voicemail" selected.
I'm fully open to the idea that this is some sort of sleep disturbance, but I wanted to check here to see if there's any possibility that a call is able to break through the blocking preferences.