LazyCAM - Mach3 Scale

We have been cutting using Mach3 and using LazyCAM to convert from DXF to G-Code. We recently updated to LazyCam Pro and now we are having problems cutting to the correct size. It is supposed to cut 18 inches tall and only cuts 4 inches. I have looked through the settings but havent had any luck solving the problem. Any suggestions?

Is the .dxf the correct size? Is the g-code incorrect, or are your steps/unit set wrong?

Sorry if this seems like a smartass question, but I don't know anything about Lazycam- is Lazycam open source software? Where would I find the source code?

Thanks,
Dan

No, it's not. A demo is included with Mach3.