Error on module activations and uninstallation

On activation/installation of the Default MERCI module (no other sub modules) I get the WSOD. After reviewing the watchdog reports I see there is an error.

PDOException: SQLSTATE[22P02]: Invalid text representation: 7 ERROR: invalid input syntax for integer: "" LINE 4: WHERE (base.vid IN ('')) ^: SELECT base.vid AS vid, base.name AS name, base.machine_name AS machine_name, base.description AS description, base.hierarchy AS hierarchy, base.module AS module, base.weight AS weight FROM {taxonomy_vocabulary} base WHERE (base.vid IN (:db_condition_placeholder_0)) ORDER BY base.weight ASC, base.name ASC; Array ( [:db_condition_placeholder_0] => ) in DrupalDefaultEntityController->load() (line 196 of /var/www/intranet.bhs.org.au/includes/entity.inc).

Also, when i try to uninstall the module I get another WSOD with the following error.

PDOException: SQLSTATE[22P02]: Invalid text representation: 7 ERROR: invalid input syntax for integer: "" LINE 4: WHERE (base.vid IN ('')) ^: SELECT base.vid AS vid, base.name AS name, base.machine_name AS machine_name, base.description AS description, base.hierarchy AS hierarchy, base.module AS module, base.weight AS weight FROM {taxonomy_vocabulary} base WHERE (base.vid IN (:db_condition_placeholder_0)) ORDER BY base.weight ASC, base.name ASC; Array ( [:db_condition_placeholder_0] => ) in DrupalDefaultEntityController->load() (line 196 of /var/www/intranet.bhs.org.au/includes/entity.inc).

I am currently running Drupal 7.14 on Postgres 8