This has been happening a lot to us in the past 10 days or so. Also, it may route the caller to the VOIPo voicemail after I pick up the phone. At about the same time this started happening, the phones switched from a display of "Incoming call on both lines" to just "Incoming call on Line 1". Do you happen to have both lines from your adapter connected to your (two line) phone instruments?

Internet connectivity shouldn't be an issue, but I stopped getting ICMP replies to pings some time ago

Pinging Voipo [174.37.45.134] with 32 bytes of data

I looked closer and the adapter now connects with something very different:

50.97.129.83-static.reverse.softlayer.com (50.97.129.83)

I don't know how long that has been the case, but I do get ping replies from it, and have lost a few replies:

Ping statistics for 50.97.129.83:
Packets: Sent = 330, Received = 326, Lost = 4 (1% loss),
Approximate round trip times in milli-seconds:
Minimum = 59ms, Maximum = 137ms, Average = 75ms
Control-Break

But this seems much more like my RT32P2 is going south, or VOIPo has changed some behavior when both lines are connected to the adapter. Only one of the two phone ports is now supplying Caller ID info in certain situations. If I use one line to call myself, it may go directly to VOIPo voicemail, and may come through as an incoming call with Caller ID. I've even duplicated the problem with answering the call and getting immediately switched to VOIPo voicemail on the calling line and dead air on the line I just answered.

Your problem is what brought me to the Forum after a long time of flawless use.