How do I stop this from showing on Step 2 of Step 3 in checkout process please?

I have Zen Cart 1.3.8a
Database Patch Level: 1.3.8

I have Paypal IPN - Website Payments Standard

It only happens with free products in checkout, if the customer buys at least one item then it disappears.

I have group pricing module A, B, (free items) C (priced items). Group A, B get the error message.

I searched forum and found someone else had same issue but were using Paypal Pro - I am not so it didn't help me.

I'm hoping someone can fix this as it does look unprofessional.

I currently have free items in my store so need it fixed.
My link is http://dees-deelights.com/store

Thank you in advance.