mnk,
Please make sure that you have DAQmx v8.0 installed. You can check what version of DAQmx you have by expanding the Software list in Measurement and Automation Explorer (MAX) and looking for NI-DAQmx. If you click on this item, the version will be displayed on the right. If you do not have version 8.0, please download it from the following website:
If that doesn't help, you should try uninstalling and reinstalling both LabVIEW 8.0 and DAQmx 8.0. LabVIEW will need to be installed first before the DAQmx driver. If your Run-Time Engine has somehow become corrupted, this should fix the problem.