I have an old Viking, 630, and it's funny you mentioned this. Just today, after having my machine for 20 years, I ordered my first walking foot, got the one from Husqvarna.
I tried it out, and it wasn't even making stitches, just thread lying there. It ended up I needed to loosen the tension on the bobbin. I've never fooled with the bobbin tension before either, but after I turned that little screw, no more problem with stitches.
When this foot came, it was packed with a little plastic pillow type thing, full of air for shipping. We had fun with it, it looked to me like this came all the way from Sweden. My one dog was sure interested in it, maybe it was air from near where a Swedish dog was!