Missing argument error

After enabling and configuring an event to associate a webform with it, when a user signs up for an event, the user is presented with this error:

warning: Missing argument 2 for event_webform_signup_sign_up() in /home/goflyxc1/public_html/sites/default/modules/event_webform/event_webform.module on line 359.

I also have it set to notify the user using all three methods (block, message and email). The message didn't show up after registering, neither did the block (and I enabled the block in /admin/build/blocks).

...and no email has come thru yet.

...something isn't working...