Making LibreCAD the default app for DXF with OS X

Hi everyone,

I'm new to LibreCAD and trying to wean myself off using TurboCad 4 under virtualbox windows XP. I'm making progress and have managed to create some new house plan drawings, but would like to make LibreCAD the default application for opening DXF files. Normally this is easy with OS X but for some reason it doesn't seem to be possible with LibreCAD. When You set up the default app and click on an existing DXF drawing, LibreCAD opens with an empty document and not the file you wanted to open.

Anyone have any ideas what's going wrong?