How to ignore certain script files / lines when debugging?

Looks like you're looking for Visual Event.

You might want to take a look at Paul Irish's Re-Introduction to the Chrome Developer Tools, in particular the Timeline section (starts around 15 minutes into the video.)

You can start recording all javascript events - function executions (with source lines etc) and debug based on what events fired. There are other really handy debugging tools hiding in that google IO talk that can help you solve this problem as well.

If you're pretty sure it's a jQuery event handler you can try to poke around with the jQuery events. This will overwrite all the click handlers (replace with the type you're interested in) and log out something before each event handler is called:

var elem = document.body; // replace with your div
// wrap all click events:
$.each($._data(elem).events.click, function(i, v) { 
    var h = v.handler; 
    v.handler = function() {
      // or use 'alert' or something here if no Dev Tools
      console.log('calling event: '+ i);
      console.log('event handler src: '+ h.toString()); 
      h.apply(h, arguments); 
    };
})

Then try calling the event type directly through jQuery to rule out that type:

$('#your_div').click()

You can use JavaScript Deobfuscator extension in Firefox: https://addons.mozilla.org/addon/javascript-deobfuscator/. It uses the same debugging API as Firebug but presents the results differently.

In the "Executed scripts" tab it will show you all code that is running. If some unrelated code is executing as well it is usually easy enough to skip. But you can also tweak the default filters to limit the amount of code being displayed.

If using are using IE 7.0 onwards, you should have developer toolbar from where you can debug. Just use breakpoint where you need, rest of the code will not stop. Alternatavely you can define other applications like Interdev/ Visual Studio.net for debugging purpose too.