What version of the DAQmx driver are you using? It sounds like you have not installed support for LV 8.0 when you installed the driver. I would recommend trying to reinstall the lastest version of the DAQmx driver.
Abhinav T. National Instruments
Abhinav T. Applications Engineering National Instruments India
LabVIEW Introduction Course - Six Hours Getting Started with NI-DAQmx Measurement Fundamentals