Nvidia System Monitor with Cuda running

Hi all,
I’m running SETI@Home with three 8800gt and has three Cuda threads. However, the Nvidia system monitor tools only show two GPU is having load while the third one is not having a load. This this a glitch in the program or is my 3rd 8800gt really not doing any work?
The attachment can probably explain it better too =P
Cuda.jpg