ZeroLink: unknown symbol '_VDSetVideoParamValue'

[Dr. William H.A. Beaudot]

Hi,

I attempted to use ioxperts public API with the beta driver 1.1b30 to 
control my Orbit camera's pan/tilt position (in a Xcode project).
At execution time, I systematically get:

ZeroLink: unknown symbol '_VDSetVideoParamValue'

What did I do wrong? or forget to do something obvious? Do I need to 
link my code to a specific framework???

Thanks,

William