lighttpd vs apache problem

I have two webservers.
Local: Apache 2.2
Remote: Lighttpd 1.4.13

I'm using the following rewrite rules:
Apache:

Code:

RewriteEngine  on
RewriteRule ^/(css|gfx|js)/(.*)	/director.php?path=$1&url=$2	[L]

Lighttpd:

Code:

url.rewrite =  ("^/(css|gfx|js)/(.*)" => "/director.php?path=$1&url=$2")

When I try to reach http://mydomain.com/js/test.js?_=1233178574125
The variables in director.php is:
$_REQUEST['path'] = js
$_REQUEST['url'] = test.js on apache
$_REQUEST['url'] = test.js?_=1233178574125 on lighttpd

Anyone understands why?

The ?_=1233178574125 string gets added when im using ajax requests (jquery), is it possible to remove that?
I think it is a caching mechanism... that the files doesn't get cached...