Fatal error: Cannot use object of type PEAR_Error as array in ..

Hello!

I have this problem with this module at the page /admin/pgdata/pgsettings/roboxchange :

Fatal error: Cannot use object of type PEAR_Error as array in ../drupal6/sites/all/modules/contrib/pgapi/pg_roboxchange/pg_roboxchange.module on line 108

Before I install PEAR XML_Serializer (http://pear.php.net/package/XML_Serializer/), I have the following error:

require_once(XML/Unserializer.php) [function.require-once]: failed to open stream: No such file or directory in file ../drupal6/sites/all/modules/contrib/pgapi/pg_roboxchange/pg_roboxchange.module on line 73.

Please, fix it! And thank you for that module.