One thing to pay attention to is that the kit gyro is limited to 250 degrees per second rotation rate. If your robot spins faster than this, then you will "upset" the gyro, and your orientation will be lost.
You can test your robot's rate by timing multiple rotations at full commanded rotation rate. If it is too fast (very likely, depending on gearing), you could scale the rotation rate to not achieve 250 dps.
If you don't want to throttle the rotation rate, check out a digital gyro. We are using one from Pololu. This thread has our code and more info:
http://www.chiefdelphi.com/forums/sh...d.php?t=127677
No matter what you do, you still will probably have drift or upset problems. Make sure you give your drivers a gyro reset button, so they can make the world right again for the robot.