Sorry, that’s my fault. preg_replace doesn’t take g as a modifier for global replacing. Just remove the g at the end of it, and it should work fine.
As for your other question, based on the number I’d say it’s replacing any character of ASCII value 34 with a single quote character - which is odd, since I’m fairly sure that’s what it is anyhow.
Warning: preg_replace() [function.preg-replace]: No ending delimiter ‘/’ found in /home3/recordau/public_html/oil-testimonials/sendEmail.php on line 313