Assignment

I'm getting an error when creating the databases, it says "assignment tables could NOT be set up successfully". These were the messages I got before the final error mentioned above: Warning: pg_exec(): Query failed: ERROR: relation "mdl_assignment_id_seq" already exists . in C:\apache2\htdocs\elearning\Learning Management Systems\moodle-1\moodle\lib\adodb\drivers\adodb-postgres64.inc.php on line 477 ERROR: relation "mdl_assignment_id_seq" already exists : ERROR: relation "mdl_assignment_id_seq" already exists Error (postgres7): CREATE TABLE mdl_assignment_submissions ( id SERIAL PRIMARY KEY, assignment integer NOT NULL default '0', userid integer NOT NULL default '0', timecreated integer NOT NULL default '0', timemodified integer NOT NULL default '0', numfiles integer NOT NULL default '0', grade integer NOT NULL default '0', comment text NOT NULL default '', teacher integer NOT NULL default '0', timemarked integer NOT NULL default '0', mailed integer NOT NULL default '0') Warning: pg_exec(): Query failed: ERROR: relation "mdl_assignment_submissions_id_seq" already exists . in C:\apache2\htdocs\elearning\Learning Management Systems\moodle-1\moodle\lib\adodb\drivers\adodb-postgres64.inc.php on line 477 ERROR: relation "mdl_assignment_submissions_id_seq" already exists : ERROR: relation "mdl_assignment_submissions_id_seq" already exists Error Can anyone help?