When I click on the "What's This" link after the "Card Security Code" field on the Payment screen, the CVV2 info pic shows up briefly, then it dissapears and the page refreshes and it goes away.

Your

<a onclick="showPopup();"

should be

<a onclick="return showPopup();"

or

<a onclick="showPopup(); return false;"

to prevent form submission.

This is in Chrome.

I made the change you suggested and it worked like a champ thanks again for the code snippet! This change is in the next release of the cart version 2.88