I'm using Mex files in Matlab to acquire signals from the NI4351 (PCI) with TBX68T. It compiles (Visual C++ 6.0) and generates the DLL with no errors, but when I execute it, a message "No driver error" is given. The same message is found if I try to run a C program. I'm using NI-DAQ version 7.1 and NI435x version 2.1 under Win98.