Enewsletter_subscription not working with PopUps Pro

The enewsletter plugin is working fine for all cases except when used with the Pop Up Pro plugin.
- I am able to register subscribers using the widget on the sidebar.

Working with Pop Up Pro
I have used the shortcode: [enewsletter_subscribe show_name="1" subscribe_to_groups="1"] for displaying the enewsletter subcription form. It displays properly.

- The subscribe button was not working. I modified the code of the button from:
<input type="button" id="new_subscribe" class="enewletter_widget_submit" value="Subscribe" />

to

<input type="submit" id="new_subscribe" class="enewsletter_widget_submit" value="Subscribe">

Now the button submits as expected, but, the desired action is not executed. It doesn't add the subscribers to the members list.

I have tried all options in configuration of the PopUps Pro plugin, but to no avail.

I configured the PopUp - > Load PopUp using -> FPage Footer, but it loads the Header of the PopUp and the remaining content being displayed on the PopUp is content from the page and not what I have configured for that PopUp.

Also, just for the purpose of testing, I also tried the popup with the Subscribe By Email form. But that also doesn't work.

Please help.