warning: date_parse()

I get this error after entering a event:

* warning: date_parse() expects parameter 1 to be string, array given in /apps/opt/drupal/sites/all/modules/event/event.module on line 2680.
* warning: mysql_real_escape_string() expects parameter 1 to be string, array given in /apps/opt/drupal/includes/database.mysql.inc on line 400.

In IE7 and FF3

Drupal 5.9
Configuration file Protected
Cron maintenance tasks Last run 41 min 4 sec ago
You can run cron manually.
Database schema Up to date
File system Writable (public download method)
JQuery Update Installed correctly
The current installed version of JQuery is 1.1.2
MySQL database 5.0.45
MySQL database for event module 5.0.45
PHP 5.2.6
PHP register globals Disabled
Unicode library Standard PHP
Operations on Unicode strings are emulated on a best-effort basis. Install the PHP mbstring extension for improved Unicode support.
Web server Apache/2.0.59 HP-UX_Apache-based_Web_Server (Unix) mod_perl/1.99_16 Perl/v5.8.8 DAV/2 mod_auth_kerb/5.0-rc6 PHP/5.2.6