I have a model made up of mulitple linked blocks that I want to insert into the final model. However, everytime I try to import it, I get the window saying certain blocks already exist and offer keep/replace/keep both. Prior to the import I purged the model of unused blocks, and restarted Rhino. Block manager does not show the blocks that eventually are said to exist when I do the import. It almost seems like they are not really purging.