Debuggin wordpress theme

I’m using Nusphere with xdebug for my php enviroment and this always works fine. Now I have a problem debugging my own theme, it seems that I can only debug the wordpress “core”…I can set a breakpoint in various file, but for example if I set a break onto /theme/mytheme/index.php or home.php the debugger never stops here!
What I have to do? I think is because the hiding url of the wordpress core? like this localhost/wordpress/?cat=3 in this case it has to call the file of my theme that I interested for.
Thanks for help