[Johnbot]

In the constructor for RobotDrive, if you pass it numbers, it will construct Jaguars for you.
So, but constructing your own, you created two Jaguar objects for the Jaguar on PWM 1, but you can only have one object for each Jaguar, so it crashed.

Just replace

RobotDrive drive = new RobotDrive(1, 2);

with

RobotDrive drive = new RobotDrive(leftdrive , rightdrive);

Edit: Also, if you never use leftdrive or rightdrive, you can just remove the code that says

Jaguar leftdrive = new Jaguar(1);
       Jaguar rightdrive = new Jaguar(2);

because the RobotDrive constructor will make them for you, though I like having the Jaguar/Victor/Talon objects declared, it just looks nicer.