Try this:

{{block type="core/template" name="contactForm" form_action="{{store direct_url='contacts'}}/index/post" template="contacts/form.phtml"}}

Try this:

{{block type="core/template" name="contactForm" form_action="{{store direct_url='contacts'}}/index/post" template="contacts/form.phtml"}}

OR

{{block type="core/template" name="contactForm" form_action="/contacts/index/post" template="contacts/form.phtml"}}