Stopwatch - missing using directive?

[salmo]

All of a sudden I have a problem with the Stopwatch class. It throws a missing using directive error. I know that this class in held in System.Diagnostics, but when I open that directive the stopwatch is not there.

using System;
using maddox.game;
using maddox.game.world;
using System.Runtime.InteropServices;
using System.Text;
using System.Collections;
using System.Collections.Generic;
using maddox.GP;
using System.Threading;
using System.Diagnostics;

public class Mission : AMission
{
    Stopwatch timer = new System.Diagnostics.Stopwatch();  // missing using directive
    Stopwatch timer = new Stopwatch();  // missing using directive
}

Any ideas what's going on? I've used stopwatch many times before without any problems.

[salmo]

[SOLVED] - Repaired the .NET client installed on my machine, must have got corrupted somehow.

[Smokeynz]

I stopped using stop watch timers, ok when doing 2 or 3 timers, but found if you have more it is difficult to keep track of stuff.
I also had a number of occasions where the timer would fail, unknown reason(broken spring maybe)

They appear to be range limited aswell.

I much prefer the tick counter as it appears to be the base of the engine time management

Time.tickCounter()