s2 member open regist form not sending email

I have setup s2 member pro plugin at http://www.numberly.com.au

At the form below the banner, I have used PAYPAL PRO FREE REGISTRATION FORM and it is working perfectly, sending email with password to customer after they sign up.

At the other places like at the extreme top right “SIGN UP NOW” button and “SIGN UP” button at the pricing table, below in the same page, when some one is registering through these links, it is not sending emails to customers with passwords, rest of the process is working perfectly fine.

The signup now (top right corner) and sign up (pricing table) are linked to this form,
http://numberly.com.au/wp-login.php?action=register

It was working fine earlier but for unknown reasons stopped working.
Paypal process is working fine in both cases.

It was working fine earlier but for unknown reasons stopped working.

That’d odd. But the user is being able to register, right?

You could try the tips in these articles:
Knowledge Base » Common Troubleshooting Tips
Knowledge Base » Troubleshooting Email Delivery Problems