[Greg McKaskle]

When you gun the motors, you are drawing so much energy from the battery that one of the issues mentioned above is happening.

1. You could be tripping a breaker. I kinda doubt this, but it is one thing that can happen when you overload a circuit.
2. The cRIO or radio, both necessary for keeping the motors running, are rebooting since the voltage dropped too low.

You can probably force this to happen simply by driving the robot up to a wall and then going forward on the joysticks slowly. The robot wheels may slip too much, but if they have good traction, you will pull lots of energy and find the weak link.

There are three likely candidates.
1. Your battery is already low. Charge it.
2. Your radio is wired directly to the special voltage boosted circuit on the end of the PD.
3. Your gear ratio is too high, or wheels are too large. Either of these will cause the motors to pull too much current for too long.

Check all of these, eliminate some of the easy possibilities and let us know what happens.

Greg McKaskle