if you read the readme file included in the package it states you need to apply a patch to your XOOPS
you can find the patches directory in xoops_trust_path/modules/protector/patches included in the protector package.
Quote:
= NEW FEATURE SINCE 3.3: DBLayer trapping anti-SQL-Injection
This feature can beat almost malicious SQL Injection attacks if you uses some modules vulnerable to "SQL Injection".
However, you have to patch a file "class/database/databasefactory.php" to enable the feature.
I prepared patches/ folder, and it contains patched databasefactory.php for each cores.
Of course, I welcome if each core teams adpot the patches as HEAD 