When importing data through activeresource it is to be expected that the data model is similar to your own. In our case:
We import clients, each clients has an address. ActiveResource tries to create the Client object but fails since there is already an Address object in the root namespace that is different. This should be solved by using XML namespace or at least a custumizable namespace.
I created a patch that solves this problem (ugly) by adding an object_prefix to each resource created to ensure uniqueness.
It works but i'd like to see an implementation with modules or some neater form of code.