Mef,
I had a look at your dxf in LazyCam and the upper radius does not look good and you had disconnected lines.
These must be saved in 11/12 ASCII AutoCad type files to be used in LazyCam.
I redid this one for you so give it a try and I'm also including the LCam file for you as well.
As for why only partial shows in Mach 3, I'm guessing you don't have this registered or if you're pocketing or offsetting, you'll need to buy the Pro version.
Dave