Strange code appears in billing form at checkout using woocommerce

Hello, I am using woocommerce 2.5.5 (latest version as of today) in my website. Everything runs fine, except that if a customer buys a product, in the checkout page there is a form to be filled out. The form is created by woocommerce and has text fields for name, address, etc. In the email field, the text field shows the following:

<span id=

then the following text fields in the form have been pushed down and the following appears in between (just “floating in the page” and not inside any other text field from the form):

email hidden; JavaScript is requiredmyemail.com” />

I can “erase” the text inside the email address and type my own, and the email link that is “floating” in the page is clickable and will open my mail program as if there is a mailto instruction….

What can I do to make the form appear normal?

Many thanks for your time