Did you add a Garmin Emulator as output of GpsGate? If not, you need to do this. Simply click the output tab of GpsGate, select "Garmin Emulator" and click add.
You also need to configure Garmin Que to connect to the proper port. Check the Garmin Que manual for details on how to do this.
If you still can't get it to work, please describe your setup in more detail.