Guest Checkout Issue

We seem to behaving a problem since upgrading to a new version of CS Cart where returning customers who have previously placed orders and checkout out as guests are being met with a message with words to the effect of 'your email address already exists, log in' but obviously they don't have an account to log in to.

Anyone have any solution to this issue?

Try to reproduce the issue on the demo and post it to the bug tracker

demo.cs-cart.com