 			if (index > length)
 				return false;
 
-			_data.splice(index, _format.dwordsPerVertex);
+			_data.splice(index, _format.size);
 			
 			if (_locked)
 			{

			
			_data[offset] = value;
			
			offset %= _format.dwordsPerVertex;
			if (value < _minimum[offset])
			{
				_minimum[offset] = value;

		public function unlock() : void
		{
			if (!_locked)
				throw new Error('Cannot unlock a stream that is not locked.');
			
			var invalidMinMax : Boolean = _invalidMinMax;
			
