I've noticed that during my maps initial load, the base layer which is set as the base layer is queried as well as another base layer.
In the example I've attached, the Google Terrain layer is set as the base layer, but the NOAA chart layer also is queried during the initial load.
To try and trace where the load is being caused, I added a "loadstart" event to the NOAA GeoTiff layer. I then discovered the "enforceOneVisible" is getting called which in turns calls the layers "setVisible" function which I believe initiates the unwanted query.
Further testing reveals that the call to OpenLayers "setCenter" function is what seems to trigger the load. The is called during the map's initialization function, in the example file it is the "realTimeMapInit" function.
I used Firefox's Firebug debugger to debug this issue. By watching the Net traffic I could see the unwanted WMS query.