Custom app: select phonenumber, press key to call

[de_peter]

I've written an application that should allow a user to press a key to call a selected phonenumber.
The following C# code will send the command to the Mitel Unified Communicator Advanced 6.0.

// Execute the Mitel SDK command
var cmd = new TelephonyProxy.Commander();
cmd.Dial("0" + phoneToCall);
Log("Commando verstuurd naar telefoonsoftware: Dial 0" + phoneToCall);

Now this used to work but for some reason it doesn't anymore.
It just executes the command, without any exception but does nothing...

Does anyone have any idea? This code used to work but stopped a few weeks ago for no apparent reason (I was playing with the .Net version of my application).