[Al Skierkiewicz]

Wow, this thread went pretty far in just a few hours.
If the drive motors are all cutting out at once, this points to something in the 40 amp wiring, if you are using that. Remember that the black wiring is just as important here as the red wiring. That being said, the problem could be in either the 40 amp block or the Rockwell block. In the order of failures these problems are:
1. Improperly stripped and terminated wiring in the Rockwell Block. Strip 5/8" and do not tin the wires before insertion.
2: Improper termination of the input side of the 40 Amp Maxi Block. Better termination can be made by stripping the input wire about 1-1/4" and folding over the stripped wire before insertion in the Maxi-Block. If you use a #6 wire straight into the block, the strands tend to ride the threads of the clamp screw up the side of the hole and prevent them from becoming part of the connection. Folding over the wire, fills the hole and allows the best clamp when the screw is tightened.
3. Loose jumper strip mounting hardware.

If power is being lost to other robot systems or if your Anderson connector is getting hot, the likely cause is scratched surfaces on the Anderson connector. Often teams use the alligator clips on the charger to connect to the open Anderson connector on the batteries. This raises scratches that reduce the amount of current carrying metal to a fraction of the design surface. The resulting high resistance connection causes heat and a voltage drop across the connector. Spend the money to buy an extra Anderson connector kit. Remove the alligator clips and replace them with the Anderson connectors. You will have to strip the wires from the charger at least two inches and fold them twice to be able to solder into the connector if you con't have the proper crimper.
Breakers do go, bad but rarely. Hot breakers trip more easily than those at room temperature. These are temperature contolled devices after all. (that includes the main breaker.) Hot wiring conducts it's heat to the breaker it is connected to.
If the problem exists on the floor and not on blocks you should suspect loose wiring that is pulled or pushed by the robot frame when on the blocks. Or on rare occasions, wiring is contacting the frame and is shorting out that branch circuit. Suspect any wiring that passes through frame tubing. An errant drill may have put a hole in the tube and damaged the wiring running through it.
As to unbalanced current in a two motor transmission, suspect that the speed contollers are not calibrated. Although rare, a motor does go open and therefore no current flows. If the current draw does approach the same current at a higher speed or load, check the calibration. It is simple to move your joysticks while watching the LEDs on the Victors. Watch to see that both light the LED fully at the same point on the joystick.