Warning message - Cannot use a scalar value as an array

Hi,
I have installed Forward module in a Drupal (5.3) multisite installation with 3 site.
The module is working and I like it (thanks for creating and mantening it).
Just in one I have activate the block "Most emailed". The block is visible but, when I have try to configurate (for changing the title, the site is for italian public), on the block configuration page Drupal show me this message:

    * warning: Cannot use a scalar value as an array in /var/www/vhosts/mysite.it/httpdocs/includes/form.inc on line 1583.
    * warning: Cannot use a scalar value as an array in /var/www/vhosts/mysite.it/httpdocs/includes/form.inc on line 1583.
    * warning: Cannot use a scalar value as an array in /var/www/vhosts/mysitei.it/httpdocs/includes/form.inc on line 1583.
    * warning: Cannot use a scalar value as an array in /var/www/vhosts/mysite.it/httpdocs/includes/form.inc on line 1583.

I have see a patch, here, but is for the 4.7.x-1.x-dev and is of July 2006.
So, before to continue the installation, I prefere to ask.
Thank you.
Kikko