Hey -
This mod is designed to use boolean fulltext queries so I believe it only works on mySQL 4.0.1+ (see
http://dev.mysql.com/doc/mysql/en/Fulltext_Boolean.html). However, if you remove "IN BOOLEAN MODE" from the query in the mod I suspect it might work okay. You just wouldn't get the benefits of boolean modifiers.
If you try this out please let me know your results.
Peace,
-Y