help with gcode files

i can create the g code from surfcam 2dfree and save it as an .nc
file and it simulates fine in the built in surfcam simulator and
also fine in "cnc simulator" and "cutviewer mill"
but when i try to load it into Kcam or master5 i get the large
circles to the left and bottom of the paths display that are
attached to the toolpaths. whats the problem here? am i doing
something wrong??
also can anyone tell me the correct way to make a dxf file that
converts with z axis g and m code too in Ace converter.i can do a
single cut path but i dont know how to impliment the z axis code
into the result in order to get to mill a part with some depth tp it
other than just one pass.

thanks