1st i installed 0004 version and due the mb_ string problem i swiched back to 0002 version. now i upgraded using patch to 0003 version but again the error come - below is the error. this mb_ error comes in many places. Is there a solution for this. pls help

"Call to undefined function mb_ereg_replace() in /home/fotomaal/public_html/inc/utils.inc.php on line 120
"