Have you checked if you are using the correct version of Xdebug? The wizzard will help you pick the wright version http://www.xdebug.org/wizard.php.
I don't know which OS you using but I guess it is Windows. I had a similar problem with netbeans on Unbuntu and Windows (Xdebug and Netbeans are not communicating with each other). Because Netbeans and Eclipse appear to share a lot of common elements this might help. Set you port number to 9001 inside eclipse.
EDIT:More info
This is my configuration:
XAMPP Version 1.8.1. Windows 7 Eclipse PDT 32bit version Xdebug 2.2.1
My suggestion is update everything to the latest version or to use the exact same configuration.
In my php.ini file (C:\xampp\php\php.ini) I have the following settings. You can access php.ini via the Controle panel -> Config -> PHP (php.ini).
[XDebug]
zend_extension = C:\xampp\php\ext\php_xdebug-2.2.1-5.4-vc9.dll
;xdebug.profiler_append = 0
;xdebug.profiler_enable = 1
;xdebug.profiler_enable_trigger = 0
;xdebug.profiler_output_dir = "C:\xampp\tmp"
;xdebug.profiler_output_name = "cachegrind.out.%t-%s"
;xdebug.remote_enable = 1
;xdebug.remote_handler = "dbgp"
;xdebug.remote_host = "127.0.0.1"
;xdebug.trace_output_dir = "C:\xampp\tmp"
;xdebug.remote_port="9000"
;xdebug.remote_autostart = 1
;xdebug.remote_mode=reg
;xdebug.idekey=netbeans-xdebug
xdebug.remote_enable=on
xdebug.remote_handler=dbgp
xdebug.remote_host=localhost
xdebug.remote_port=9000
AND turnoff report zend debug in php.ini
; This setting is on by default.
report_zend_debug = 0
Xdebug Configuration inside Eclipse:
Start Eclipse -> Explorer window -> File -> Properties -> PHP -> PHP debug -> Select under default settings Xdebug instead of Zend. (If needed configure: Xdebug to port 9000).