Bad PG sql syntax

Not sure if I am posting this issue in the correct place, if not I am sorry:

I used this module to import CSV multichoice questions and for each question imported I get multiple errors like this:

warning: pg_query(): Query failed: ERROR: syntax error at or near "REPLACE" LINE 1: REPLACE INTO quiz_multichoice_user_settings ^ in /var/www/sparcs/includes/database.pgsql.inc on line 139.
user warning: query: REPLACE INTO quiz_multichoice_user_settings (uid, choice_random, choice_multi, choice_boolean) VALUES (1, 0, 0, 0) in /var/www/sparcs/sites/all/modules/quiz/question_types/multichoice/multichoice.classes.inc on line 666.

Franco