question from newbie

Hi, I have finally got my desktop cnc router up and running, I tried doing the exercise in Cambam to cut a stepper plate, I managed to get the g code into the machine, however when I started it, the cutter moved to the start point then I got an error message saying "radius to end of arc differs from radius to startline 33". I have poured over the printout of the program but don't have a clue where to look for the problem, I understand the symbols etc. but nothing makes sense to me.
Any help you can offer would be appreciated.
Thanks
Terry