NetworkAvailability event won't fire or handler isn't seeing it

[RobinS]

My application needs to know when the network availability has changed and
do some stuff when it does.

I wrote a small WinForms app to test System.Net.NetworkAvailabilityChanged.
It works great.

I put the same logic in my main application, and the event is never caught
by my handler.

If I put in NetworkAddressChanged, it *is* fired and caught. But I don't
need to know if the address changed, I need to know if the user is online or
not.

Here's my code:

In the constructor of my main form after InitializeComponent(). (Note: It
doesn't work if I move it to the load event either.)

updateNetworkStatus(NetworkInterface.GetIsNetworkA vailable());
NetworkChange.NetworkAvailabilityChanged +=
new
NetworkAvailabilityChangedEventHandler(myNetworkAv ailabilityChangedHandler);

And here's my event handler:

private void myNetworkAvailabilityChangedHandler(object sender,
NetworkAvailabilityEventArgs args)
{
updateNetworkStatus(args.IsAvailable);
}

And here's the last method:

private void updateNetworkStatus(object state)
{
//do stuff
System.Diagnostics.Debug.Print("***Network status changed to {0}.***",
state.ToString());
}
One blog I found recommended this in the event handler:

this.Invoke(new WaitCallback(updateNetworkStatus), args.IsAvailable);

instead of just calling updateNetworkStatus.

That doesn't work either, and I'm not sure why I would use that over just
calling it.

Any help or advice would be greatly appreciated.

Thanks,
RobinS.
GoldMail.com