[xdebug-general] XDebug2.1 not working after installation on Windows7

Hi all. I'm a big fan of xdebug and always used it in my linux dev
environment, so today i tried to install it in my fresh new windows7
installation. I configured my windows7 to run apache2 from
http://www.apachelounge.com/ and the last php5.3.6 VC9 x86 NTS. I followed
the instruction for installation, downloaded php_xdebug-2.1.1-5.3-vc9.dll
and put it under php/ext. Then i successfully edited my php.ini file and
restarted apache.

In php.ini:
zend_extension=C:\Program Files\PHP\ext\php_xdebug-2.1.1-5.3-vc9.dll

In phpinfo() output:
This program makes use of the Zend Scripting Language Engine:
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies
    with Xdebug v2.1.1, Copyright (c) 2002-2011, by Derick Rethans

Even if the extension seems to be correctly loaded the output of var_dump()
and error reporting is not changed as i was expecting. Should I enable
something in the php.ini?
Thank you

-- 
Giacomo Galilei
Senior Software Architect
3rdPLACE
www.3rdplace.com
Sede di Milano
viale Coni Zugna 5
Tel. +39 02 76281064
Sede di Roma
 Via Galilei 45
Tel. +39 06 48905684