I have created a part with an external reference which I broke immediately, and used it in a subassembly.  I later copied this entire subassembly into a second folder.  So, I have two sets of files with the same name in different folders.  I subsequently noticed some cross linking.  The subassembly in folder B would open a part in folder A instead of the same part in folder B.  While examining the links for the subassembly in folder B in SolidWorks Explorer, I noticed that the part with the broken external reference showed a link back to a part in folder A.  I deleted the part if the external reference from the subassembly in folder B and saved it.  I checked in again in SolidWorks Explorer and all cross links between folder A and B were gone.  So, by question is, is there a way to eliminate from a part any "memory" at all of an external reference?  Apparently it isn't enough to break it.  PLEASE, no lectures on having two files with the same name.  PLEASE.