Yes, as SDM said above, we had lots of problems at our first regional. We tripped both the main breaker and the 20 and 30 amp ones. So, if our robot wasn't moving in jerks across the field, it was dead.
Anyways, we really cut down on the friction at NYC (second regional for us) and we had a huge power increase. Not only did we stop tripping breakers (any of them) we had a huge increase in the speed and power of our robot. As Dan said, if the problem is not electrical, make sure your drivetrain has as much graphite, nylon washers (to reduce friction and contact between parts), and anything else that might produce friction. You'll be amazed at the amount of power that your robot now has.
I know i was.
Also, make sure your frame is not grounded (by the light or anything else) cause that was tripping some bots i saw.