when you search for the database to load in Vsig, pay attention to the File Type field in the window opened by Vsig. It offers 3 choices:
Binary Files (*.sbs) > This won't obviously look for .sbf files
Text Files (*.sbf) > This WILL load an .sbf file!
All Files (*.) > will show every type of file in a directory.
It's just the way Windows and Vsig may look at different type of files.
Tricky, but works!