Hi Balsaman,
I can't help you specifically, but machines will do some weird things if the controller gets confused with a command that is incorrect in syntax.
Take my Shadow controller for example: if I have anything on a line with a tool offset command, the machine immediately rapids all the way down to the Z- limit This is obviously a case of where the software people did not properly trap for incorrect syntax.
So I'd suggest that you take a look at your arc commands, make sure they are laid out exactly as "the book" says they should be, and that you are using correct arc center coordinate format. Do not include any other commands on the same line as the arc command, to try to isolate the issue.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)