OK, a few things...
You should create instances of the objects that you are going to use in the RobotInit method (or some other code that will only be executed once). In your original post at the top of the thread, you are creating the RobotDrive instances in TeleopInit() which means it won't be available in your Autonomous code since it hasn't been created yet.
So I would move all the sensor and actuator creation code to the RobotInit method since that will only be called once per run of the robot. That ensures you won't be trying to recreate something or forgetting to create it on either the autonomous or teleop path.
Also in the last post you did something like this:
Jaguar leftdrive;
Jaguar rightdrive;
RobotDrive drive = new RobotDrive(leftdrive, rightdrive);
In this case you are allocating two references to Jaguar objects, but you have not yet allocated the objects themselves. This is done using the new operator. So what you need is something like this:
Jaguar leftDrive = new Jaguar(1);
Jaguar rightDrive = new Jaguar(2);
RobotDrive drive = new RobotDrive(leftDrive, rightDrive);
Here the leftDrive and rightDrive Jaguar objects are allocated before using them to create the RobotDrive object.
You also might want to look at RobotBuilder to create this part of the program since it will create the structure of the program for you with all this housekeeping already done in the generated program. There are some videos that describe how to use it in:
http://www.youtube.com/user/bradamiller.
and more documentation:
http://wpilib.screenstepslive.com/s/3120/m/7882
Good luck!
Brad