Hello Jeffery,
I would recommend you verify that all the parameters are being passed correctly -- debug your CVI application or print them to standard out before calling the DLL. Also, check to make sure that the calling convention of the DLL and your CVI application match. You might also try calling the DLL from another programming environment (other than LabVIEW) to determine if the problem is specific to CVI or to the way you are calling the DLL. The Developer Zone is also a great resource, go to:
http://zone.ni.com/
Then click on RESOURCE LIBRARY >> LABVIEW >> CONNECTIVITY >> DLL INTEGRATION >> "Creating and Calling LabVIEW DLLs with Various Data Types from CVI"
If this does not help, you may consider contacting NI's email support at http://www.ni.com/ask
J
eremiah
Applications Engineer
National Instruments
http://www.ni.com/ask