Seg fault in PHP 5.0.5

Has anyone had any problems with PHP 5.0.5 getting seg faults when trying to replace extended ascii characters? I'm trying to replace the following characters: Â °, with " degrees". I am able to detect these characters in the string, but when I try replacing it, PHP seg faults. I've tried both str_replace() as well as preg_replace(). I've tried replacing the characters by pasting them directly, using chr(176) & chr(194), and even \xC2 and \xB0. I get the Segmentation fault both through Apache as well as CLI (command line interface) consistently. Any ideas? Thanks, Dean Householder