Invalid IL Code Error

I've reduced the code to the relevant parts. I thought maybe the enum was the problem (_type used to be an enum) and even made the parameters 0. I'm still getting the error.

Spoof, is a script attached to the GameObjects that the OverlapSphere is looking for, and it contains values for scanPower, thermalPower, laserPower. (But that's probably not relevant.)

I get no compiler errors. Just this at runtime:

InvalidProgramException: Invalid IL code in Missile:CheckSpoof (int,single): IL_001f: call 0x0a00004e

 var target : GameObject;
 _spoofed : boolean;

 function Update () {
     CheckSpoof(0, 0);
 }

 function CheckSpoof (_type:int, _spoofResistance:float) {
     var _hitColliders = Physics.OverlapSphere(target.transform.position, 1000);
     for (var h=0; h < _hitColliders.Length; h++) {
         var _spoofScript:Spoof = _hitColliders[h].gameObject.GetComponent(Spoof);
         var _spoofPower:float;
         if (_type == 0) { _spoofPower = _spoofScript.scanPower; }
         if (_type == 1) { _spoofPower = _spoofScript.thermalPower; }
         if (_type == 2) { _spoofPower = _spoofScript.laserPower; }
         if ( Random.Range(0.00f, 1.00f) <= _spoofPower * (1 - _spoofResistance) ) { // spoofed!
             target = _hitColliders[h].gameObject;
             _spoofed = true;
         }
     }
 }