Hi Lance,
Does your iPAQ HX2790B run the Windows Mobile 5.0 operating system? If so, you will need at least version 2.1 of the NI-DAQmx Base driver for support for this OS. The most recent version that provides support for Windows Mobile 5.0 is version 2.2, and it can be downloaded
here. Let us know if this helps.
Regards,
Andrew W
National Instruments