Vex Ultrasonic Sensor not responding

[SomeoneKnows]

I've downloaded the Sensor Test code from the VexLabs site and have it compiled and running on my Vex controller. I have the Optical Encoder, Line Follower sensor, and Light sensor all working properly. I'm not getting any response from the Ultrasonic sensor.

I'm using MPLAB, C18 compiler, and Vex version of IFI Loader. I'm using the Vex_library_auton_debug.lib library. In the IFI Loader's Com Terminal Window I see everything responding properly but no response from the Ultrasonic Sensor.

Is there any way to tell if this sensor is dead?

Vince