ServoTimer2 library

Hi i've download the Servo Timer2 Arduino Playground - HomePage
and I'm getting this result when compiling

C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:6:26: error: WConstants.h: No such file or directory
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp: In function 'void __vector_9()':
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:36: error: 'LOW' was not declared in this scope
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:36: error: 'digitalWrite' was not declared in this scope
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:43: error: 'HIGH' was not declared in this scope
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:43: error: 'digitalWrite' was not declared in this scope
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp: In member function 'uint8_t ServoTimer2::attach(int)':
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:66: error: 'OUTPUT' was not declared in this scope
C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:66: error: 'pinMode' was not declared in this scope.

I have put them in the right place aswell. I have made sure that at ServoTimer2.h file has #include <Arduino.h> and #include <wiring.h> and also for ServoTimer2.cpp I put //#include "WConstant.h"

I need your help asap! I need to use virtualWire and servotimer2 library and I cant make it work.
Thanks!

From the sticky in Programming Questions

http://forum.arduino.cc/index.php?topic=97455.0

  1. Version 1.0 of the IDE*

A few things were changed in the 1.0 release version of the IDE. In particular some older examples and libraries may have this at the start:

Code:
#include "WProgram.h"

If you get errors try locating such places and changing that line to:

Code:
#include "Arduino.h"

  • IDE = Integrated Development Environment

Hey I'm using Dev - C++ as my compiler and I wonder why when I modified the .cpp file by including Arduino.h went well. Twas alright all of a sudden. Then when I went home and use my computer, used the same program etc and the same modification, it says the same error again. Do you guys have any clue?