Please enter valid mail address

Hi

Events Made Easy is excellent plugin. Just one problem. I have tested it from a few different dives and it works well. But a friend with a Samsung Curve recieves the following error message when he tries to book for the event: “Please enter a valid mail address.” The email address is valid. He also tried another valid address, but received the same error message.

Can anybody assest?

https://www.ads-software.com/plugins/events-made-easy/