Don,
Here's the things I'd check.

1. Open the VSS Administrator and in the "expand keywords of type" text box on the general tab, make sure that you've included an entry for each text file Fox creates/supports: *.prg;*.sca;*.vca...etc.

2. Make sure you log out and back into the VSS Explorer after setting these settings. It only checks them when it is starting up.

3. In the file that you are trying to expand keywords in, put an entry that looks like:

$Author::                      $
$Date::                        $
$History::                     $

4. Make sure there is enough room between the $ signs for the text that will be entered.

Supplemental answer: You can include the keywords in methods in forms and classes. They will not be expanded in these files, but they will be expanded in the SCA/VCA files. VSS doesn't do much of anything with binary files.