SimulRing Problem: Voipo or AT&T?

Lately, whenever I receive a SimulRing call and try to answer via my cell phone (AT&T, iPhone 4), I have to wait for instructions. A woman's voice (like a voicemail voice) comes on, states the number that is calling, then tells me to press "1" to answer or "2" send to voicemail (not sure if that's number 2's actual answer, I'm usually trying to answer the call before I get to #2). This is new. I can't remember when it started, but is fairly recent. Is this happening to anyone else? I couldn't find any settings in the VPanel other than how long to ring each number. Maybe it's AT&T? Any feedback would be great.
Thanks!
Mike