View the source of the results page and look for error messages
within html comments. You probably have permission problems.
Make sure that texis and gw are running as the same user. The installation
attempts to make texis and gw setuid to the user you specify. If they
are not, you can make them so with something like:
chmod u+s .../cgi-bin/texis
chmod u+s .../webinator/bin/gw