snowedin on "[Plugin: Contact Form 7] Redirect issue with Firefox"

I tried adding the snippet of code to the functions.php file from this thread:
http://wordpress.org/support/topic/plugin-contact-form-7-how-to-redirect-after-submit?replies=23

It fixed the redirect issue in Firefox but broke the form in Chrome (returned the infinite circle, no "sender's message was sent successfully" message either - even though the form did submit).

Any ideas?