This has been an issue since I started using SolidWorks (6 years ago). We store our macro files on a network drive that everyone can read from, but only (2) people can write to (me and another guy). If a user runs a macro from that folder, the macro file gets "locked" and we are unable to edit/rename/delete it until everyone is out of SolidWorks. We usually wait until after hours to make changes to the macro files because of this.

Since that the files are read-only, why does this happen? I brought this subject up before on comp.cad.solidworks, and it looked like other people had the same issues.