@Joan_Sparky - I have increased the size of the page to A1 see here, http://prntscr.com/fit8fs, but this has not helped, in fact I now have some weird misalignment with the top silkscreen and the rest of the board in when the Gerbers are generated, see here - http://prntscr.com/fit98f
@Rene_Poschl - I have tried in 4.5mm instead of 4.6mm and I get the same problem. In fact the Gerber view in the link above is in 4.5mm.
(@)bobc I would prefer not to post the Gerbers since this is for a commercial project.
I would guess that the number of lines shown are equal to the number of times I have imported a DXF into this design ... I have tried rebuilding from the net, but they persist.