I have added following lines into php.ini
[XDebug] zend_extension = C:\\PROGRA~1\\PHP5\\ext\\php_xdebug-2.1.0-5.3-vc9.dll xdebug.remote_enable=on xdebug.remo
zend_extension = C:\PROGRA~1\PHP5\ext\php_xdebug-2.1.0-5.3-vc9.dll
should be replaced by
zend_extension="C:\PROGRA~1\PHP5\ext\php_xdebug-2.1.0-5.3-vc9.dll"
P.S. Will e-mail xdebug guys.