Due to the changes in the daeURI class this is not working anymore. According to DOM backward compatibility - COLLADA Public Wiki i ran into the type of problem where I should ask here how to achieve the same with the new api.
I think the part in red seems to be the where your problem is. You don’t show the creation of “positions” and if it’s not placed in the same document as “pinput” then the URI won’t construct and resolve correctly.
Everything is done in the same dae. The elements were resolved correctly with the old collada dom, but this one seems as if it either isn’t able to resolve it or doesn’t resolve it at all. Do I have to call something so that the resolving takes place before i do the dae->saveAs(…)?