Table custom_breadcrumb not created

When I enable the module, I get the following warning:

user warning: BLOB/TEXT column 'visibility_php' can't have a default value query: CREATE TABLE custom_breadcrumb ( `bid` INT unsigned NOT NULL auto_increment, `titles` VARCHAR(255) NOT NULL DEFAULT '', `paths` VARCHAR(255) DEFAULT NULL, `visibility_php` MEDIUMTEXT NOT NULL DEFAULT '', `node_type` VARCHAR(64) DEFAULT 'AND', `set_active_menu` INT NOT NULL DEFAULT 1, PRIMARY KEY (bid) ) /*!40100 DEFAULT CHARACTER SET UTF8 */ in C:\Inet\htdocs\drupal-6.11\includes\database.inc on line 515.

Subsequently the table custom_breadcrumbs is not created and the module admin page shows warnings.
I'm running this on my dev machine under Win XP, PHP 5.2.9-2, Apache 2.2.current, MySql 5. No problems with other modules so far.