I'm not sure I follow the original post. The import_map is only used for imported posts when you are going from links to the old forum (prior to 7.0).
It could be a variety of things, since several things were done at the same time, moving database to new serer and upgrading.
What should have probably been done, and you still might want to do, is start with your original database on the old server and then install that exact same version on the new server and make sure it works properly. At that point you could do the upgrade. It could be something such as database alteration steps not being run.
