Form Design Page error message

Hi! I’m new at this. I’m trying to install a form to allow visitors to my blog to sign up for emails. I am using Constant Comment Form Designer. I have activated it. If I go to Appearance/widgets on the right I have my Primary Widget Area and under it is the drop down menu “Constant Contact Form Designer: Sign Up for Our Newsletter”. I start to fill it out. When I get to “Create your form on the FORM DESIGN PAGE” I click on the FORM DESIGN link. The new box opens, but at the top appears the message “Form generation error: something went wrong!” If I click on the “SAVE FORM” button, a new message appears (quite long) stating:

“Form Designer needs your help! Your web server thinks that Form Designer is an unwelcome script. Obviously, it is not. For Form Designer to work, you need to contact your web host and request that they “whitelist your design for ModSecurity.” This shouldn’t pose any risk to your website; it just lets the host know you want the Form designer to do what it does best!”

So I called Earthlink and talked with technical support. In the end I was told that if I “whitelist” ModSecurity (which they said is the same as turning it off) my sight would be vulnerable to hacking…

Any suggestions as to how to proceed from here? Perhaps a different widget? It seems there aren’t many choices for plugins in this area(?). Any help welcome!

Thank you. -John