I ran into this problem as well (after solving many, many other cascading issues...). I solved this problem by downloading the latest versions of the Courseware examples at www.ni.com/academic. I believe this included support for NI-DAQmx.
In general, I've solved may of my recent issues by downloading current versions of software, drivers, etc. It is especially important to download ELVIS 3.0 for LabVIEW 8 support.