Firebug Breakpoint Position Causes Problem

Hi

This sounds so ridiculous that I hope someone else could duplicate this:

I have a jquery ajax function in a separate js file.

var request = $.ajax({ 
	url: $url,
	type: "GET",
	cache: false,
	dataType: "html",
});

request.done(function(response) { 
     alert('done');
});

If I put a breakpoint next to "alert('done')", then the alert statement is still executed - after I clicked 'continue'.

But if I put a breakpoint next to 'request.done', then the "alert('done')" statement is not executed - or appears not to be executed - after I clicked 'continue'.

I use FF 22 and Firebug 1.11.4
I have reset FF.

Ps. The guys at Firebug probably do not experience the same problem, because they want a full example from me.

Any ideas?