Fatal error: Cannot use string offset as an array

Hello!

I'm using the cvs version of drupal.
I downloaded the cvs version img_assist module as well as the cvs version formupdater module and I have an error in the file system.module.

Here the error:

Fatal error: Cannot uses string offset have year array in/home/valerie/public_html/drupal4/modules/system.module one line 734.

With this code:

function system_settings_form($form_id, $form) {
$form['buttons']['submit'] = array('#type' => 'submit', '#value' => t('Save configuration') );
$form['buttons']['reset'] = array('#type' => 'submit', '#value' => t('Reset to defaults') );

if (!empty($_POST) && form_get_errors()) {
drupal_set_message(t('The settings have not been saved because of the errors.'), 'error');
}

And line 734 is:
$form['buttons']['submit'] = array('#type' => 'submit', '#value' => t('Save configuration') );

Can you say to me what I must do to cure it?

Please, help me because I need some for my project for training course.

Thank you in advance.