It is spawning a fixate in between the 2 objects.
I think you need to grab the geomid of the other object.
Having a search on the algodoo forums and the phunland.com forums might help you get the geom of the other object.
I think paradigm has made a tutorial else just chose a fix joint copy it to notepad or word-pad paste it and it will translate it to code you can use that to find out what the geom-id should be