I installed the latest XAMPP package which includes PHP 5.3.0. I am trying to enable Xdebug, but it just won't work.

Here's what I changed in the php.ini shipped with XAMPP:

; uncommented
zend_extension = "X:\xampp\php\ext\php_xdebug.dll"

; added the following lines:
xdebug.remote_enable=true
xdebug.remote_host=localhost
xdebug.remote_port=9000
xdebug.remote_handler=dbgp

Apache starts fine, but when I open http://localhost/ in my browser, I get the following error

If I click the Close the program button, the error message will reappear in a second as if it was in an infinite loop. I'd greatly appreciate any help in getting this to work.

I am running a fresh install of Windows 7 Ultimate 64-bit.

EDIT: From the result of phpinfo():

Zend Extension Build    API220090626,TS,VC6 
PHP Extension Build     API20090626,TS,VC6 
Debug Build             no 
Thread Safety           enabled