Static Variable crashes when accessed too fast?

Inspired by UnityCoder website, i converted a Sin Cos lookuptable code that is 10 times faster than Mathf.Sin, it worked at 10k calls per frame, until i tried to call the same array value twice in the same loop, in which case it chrashes and sais: IndexOutOfRangeException: Array index is out of range. m.cos (Single rr) (at Assets/-=TubeGlider/0N/Scripts/m.js:27)

m.sin works fine and m.cos causes error when i ask the same m.cos value twice in a frame in start function.

 m.JS -
 //Fast Sin Cos lookup table helper functions accessible by static functions.
  
 private static var  lookupTableSize : int=8192; // or 1024//16384
 private static var  mSin:   float[];//
 private static var  mCos:   float[];
 private static var  mconst: float;
  
 function Awake ()
 {
     // init arrays
     mCos = new float[lookupTableSize];
     mSin = new float[lookupTableSize];
     mconst = lookupTableSize / (2*Mathf.PI); // array index constant
     // build lookup tables
     var angle:float = 0;
     for (var i:int=0;i<lookupTableSize;i++)
     {
         mSin[i] = Mathf.Sin(angle);
         mCos[i] = Mathf.Cos(angle);
         angle += 2*Mathf.PI/lookupTableSize;
     }    
 }
  
 // helper functions
 static function sin (rr:float) :float {return mSin[(rr * mconst)%lookupTableSize];}
 static function cos (rr:float) :float {return mCos[(rr * mconst)%lookupTableSize];}