How to get collisions working on a flying controller?

I have a section in my game where the player enters a maze, colliding with a trigger that essentially disables gravity. They can then fly around in the maze. I am using the FPS Character Controller.

The problem is, the player no longer collides with anything. I've put a rigidbody on the controller, but no good.

The trigger disables the "Character Motor" script, the "MouseLook" on the Controller, and the "MouseLook" on the camera. The following code is then enabled, enabling free flight:

 var turnSpeed = 10.0;
 var moveSpeed = 10.0;
 var mouseTurnMultiplier = 1;
 
 private var x : float;
 private var z : float;
 function Update () 
 {
     // x is used for the x axis.  set it to zero so it doesn't automatically rotate
     //x = 0;
 
     // check to see if the W or S key is being pressed.  
     z = Input.GetAxis("Vertical") * Time.deltaTime * moveSpeed * 10;
 
     // Move the character forwards or backwards
     transform.Translate(x, 0, z);////
 
     zx = Input.GetAxis("Horizontal") * Time.deltaTime * moveSpeed * 10;
 
     // Move the character forwards or backwards
    transform.Translate(zx, 0, 0);  ////
 
     // Get the difference in horizontal mouse movement
     x = Input.GetAxis("Mouse X") * turnSpeed * mouseTurnMultiplier/10;
     y = Input.GetAxis("Mouse Y") * turnSpeed * mouseTurnMultiplier/10;
 
     // rotate the character based on the x value
     transform.Rotate(-y, x, 0);   //transform.Rotate(-y, x, 0); <<<
 
 }

So I can then fly around fine, but don't collide with anything.

I've been trying to figure this out for two days. I've read every single scrap of information I can on Answers etc. but I'm just not able to get it to work.

If I fly to a point within the maze, and then switch the Mouselooks and Controller back on, and the above script off, gravity re-engages, the character falls, and collisions are back to normal.

Any ideas? This is making me feel really stupid and I'm sure it can't possibly be that complicated....

Thanks in advance ;)