I'm not sure what's happening here, I have e-mailed some dxf's for laser cutting, and I have a reply telling me the dxf's are empty.
I created the dxf's by saving the drawing view like this.
I can open them and they look good to me.
The company can offer no suggestion to me as to the problem.
Really need to get this fixed in the next 30 minutes... :/
I marked Stevens answer as correct as he was first to suggest saving from the part, not from the view. This worked and fixed the problem.
I have also discovered that this seems to be a specific problem between Autodesk Trueview (used by our Laser company) and DXF's of drawing views created in Solidworks.
The alternate solution is to save a DWG of the drawing view.
Thanks again everyone