I get that once in awhile. I can only guess, but this morning I got a call from "CALIFORNIA" on the caller id. I am guessing it is a telemarketer that might be on Ooma's community black list, but the call probably went to ring me before the black list cut it off.
Like I said, I am just guessing, but it seems like the only times it happens is when it is some kind of commercial caller id.
Any of you have any other ideas?