Hi, Clint
I think what maybe causing your problem is as follows,
Mach default's on start-up to F6 feed (Feedrate 6.00), If you use the Jog key's to setup Motor Tuning, Velocity & Acceleration, Thy will be way off.
On the Program Run Screen, Click on the Feed-rate DRO line, Type in 100 then "Enter", Feed-rate is now 100.00, Units/Min will show Your Velocity setting.
OK now check the % Jog setting, Press the TAB key for "Pop-out Jog Window", Set the Slow Jog Rate to 100 %.
Now set up your Velocity & Acceleration and then give your G-code a try.
Hope this Helps, Chip