Problems with contact forms

Hi

I have a wordpress site with contact form. i was using WP-contact but checked my site the other day and it had stopped working. I checked and the plugin seemed to have disppeared from my webspace. I re-uploaded it but it disappeared again, so I tried cforms instead all worked fine when I uploaded it yesterday but today you press the submit form and it doesn’t let you know it has gone through (even though I do receive an email) yesterday my message Thank you for your email would appear. Any ideas please? Thank you. My site contact page is below
http://www.theweatherpops.com/contact