Contact Form 7 works great with IE8 then including a form in a post. But when I include the same form in the widget, then submitting the message fails (The arrow rotates infinitly. Nothing happens after pressing the button.)
But if any Contact-Form-7 form is displayed in a post AND the contact-form-7 widget is engaged (with another form), then contact-form-7-widget succeeds in sending an e-mail.
I tested in on 2 wordpress blogs (with different themes). One of the blogs is XHTML valid.
This is an IE Problem. Firefox is fine.