siproxd Package with 2.1

Greetings list,

Is anyone using the siproxd package with 2.1 (or even 2.0)?

I thought I'd give it a try this evening, and whilst it installs quite
happily, it seems to only bind itself to the default WAN interface, even
when told to use a different WAN (in this case OPT2).

I'll have a play with debugging it over the weekend, but thought it
might be worth asking the question here just in case someone else has
already been through this and found a solution.

TIA.

Kind regards,

Chris