I have been having problems getting my TiVos making phone calls over the Vonage phone line. I have changed one of my TiVos to use our ethernet network, but our other one does not have Home Media Option (It is a TiVo/DIRECTV box). Vonage has posted some instructions about how to get this to work. It has been hit and miss for me. Some of calls work and some don't.
Update: It looks like the HDVR2 does not support having its speed set to below 56k, so it will not work with Vonage.Â There is a post on TiVo Community Forum that talks about getting an external modem to work with it.