Missing argument 1 for icontact_sig()

I am running Drupal 5.18 / PHP 5.2.8

I have configured the iContact API with my account at iContact successfully. I see all the lists I have at iContact in my Drupal site.

I have enabled the subscription block in my Drupal site.

When I try to subscribe to the iContact newsletter in the block I get the progress bard and then a message that comes up saying, "There was an error processing your request. Please try again. If the problem persists, try again later."

Then after a page refresh I get this error as a Drupal message:

warning: Missing argument 1 for icontact_sig(), called in /home/mysite/public_html/sites/all/modules/icontact/icontact.module on line 294 and defined in /home/mysite/public_html/sites/all/modules/icontact/icontact.module on line 265.

Any ideas what can be causing this?