Well at a cursory glance it looks like the password to the MySQL database is incorrect or not specified. The documentation refers to two files config.php3 and connect.php3 one of those should have a place for the database username and password, unless the problem is deeper than what I see that should do it.
Warning: Supplied argument is not a valid MySQL result resource in /home/atbuf/public_html/phpdig/search.php3 on line 120
<!-Admin-->
Warning: Supplied argument is not a valid MySQL result resource in /home/atbuf/public_html/phpdig/spider.php3 on line 28
Spidering in progress...
Warning: Supplied argument is not a valid MySQL result resource in /home/atbuf/public_html/phpdig/spider.php3 on line 92
level 0 : more new links
Warning: Supplied argument is not a valid MySQL result resource in /home/atbuf/public_html/phpdig/spider.php3 on line 165
--------------------------------------------------------------------------------
links found :
Warning: Supplied argument is not a valid MySQL result resource in /home/atbuf/public_html/phpdig/spider.php3 on line 169
This is usually as result of a connection failure - the script is trying to pull results from Mysql when it doesn't have a connection.
Again, it looks like either the user name, password, or database name is wrong in the script.
Do you have telnet access to the server?
mysql -p -u username databasename
at the prompt. It should ask you for a password. If it lets you into mysql that way, check that the values in connect.php3 match the ones you typed.
If that doesn't work, stickymail me the connect.php3 file (don't post it here!) and I'll take a look...