My name is João Ricardo and I live in Brazil. Working in the company Psal, Primo Systems Applications Ltda. We use the Windev about 4 years and so far we have managed to develop our systems without major difficulties.
Acquire the biometric reader FingKey Hamster's Nitgen to implement in our system of fingerprint identification.
Along with the equipment received your dll's and sample programs and their sources. The sample programs were developed in Visual Basic 6 and Delphi 6. In tests with the sample programs achieved success in the use of FingKey.
Began the development of routines to access the device using as basis the documentation and the sample programs.
We observed the return of the methods of the dll was not expected, so post in the forum decided that question in an attempt to get some help.
I do not know what may be happening.
Someone has already developed something that could help me?

C++ (Documentation)

NBioAPI_Init() is the function that initializes the NBioBSP module. NBioAPI_Init()
returns the Handle of the NBioBSP module used in the application.

NBioAPI_HANDLE g_hBSP; // NBioBSP module Handle.
…
// Initialize BSP Module
if ( NBioAPI_Init(&g_hBSP) != NBioAPIERROR_NONE )
{
// Init module failed. Show error message.
}
// Init success.

Windev (my code)

ret is int

hwnd is int = SysWinActive()
IF hwnd = 0 THEN hwnd = Handle()

hInst is int = LoadDLL("NbioBSP.DLL")
IF hInst = 0 THEN
Error("Loading error")
ELSE
// Initialize
ret = CallDLL32("NBioBSP.dll", "NBioAPI_Init", hwnd)
Info("NBioAPI_Init: "+ret)
// OpenDevice
ret = CallDLL32("NBioBSP.dll", "NBioAPI_OpenDevice", hwnd, 1)
Info("NBioAPI_OpenDevice: "+ret)
FreeDLL(hInst)
END

I appreciate any help.