We have developed a software package under Labview 5. There it works fine. Running it from Labview 6 doesn't work. The startup doesn't find vi's like General Polynomal Fit.vi and so on. We do not find these files on the old machine.
In both 5 and 6.1, General Polynomial Fit.vi is in vi.lib\analysis\6fits.llb. That's assuming you have at least the full LabVIEW version and not the basic version and that the analysis package was installed.