Yep, me too, new Withings user as of yesterday, really want to integrate with Forerunner 405.
FWIW, even though I love my 405 (and loved my Forerunner 50 before that) I'm seriously considering another brand for my next HRM unless GC becomes a bit more open to integration with 3rd parties.
Seems that Garmin is not reading their forum. We've lots of people that really like to have the Withings scale connected to Garmin Connect, which is very easy to do.
I hope that anyone in Garmin can shine a light into this weird issue!
+1 for Withings support. Come on Garmin - step up already. Who uses Tanita anyway? A hundred bucks more and it doesn't even have a read out. Withings...