Also the auto join in the IGES import can get confused if there are multiple separate parts that touch each other contained all inside one single IGES file.

It will try to use the "level" assignments in the IGES file (levels in IGES are like layers basically) to only try and join together surfaces on the same level but if the IGES was generated with everything all on the same level instead of separate levels for each part that won't help.

- Michael