Javascript debugging vs. exceptions. Follow

jQuery does some testing of the errorhandling capabilites of the current browser. Specifically at line 4995 (jQuery 1.6.4) this code can be found:

     try {
            // This should fail with an exception
            // Gecko does not error, returns false instead
            matches.call( document.documentElement, "[test!='']:sizzle" );
    
        } catch( pseudoError ) {
            pseudoWorks = true;
        }

Break on exception is not enabled. I have added the path "http://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js" to "do not step into scripts", but still PhpStorm halts script-execution.

I have tried jQuery 1.5.2 and jQuery 1.6.4. It wasn't always this way, so it must be something with my setup, or a newly introdused error.

This is making javascript debugging painful.

Edit: It seems this kind of errortesting with fallback is pretty common. Even this forum caused a break in javascript-execution when I submitted this post.
Also I have tried Firefox and Pale Moon(basically Firefox) and Google Chrome.