Is there a way in Firebug to set a breakpoint in an external .js file referenced by the page so that it can go through?
(I suspect I found a bug in jQuery, and I want to be able to go through jQuery as it handles events to see what it does.)
Not sure if I understand the question, but I don't think Firebug treats external javascript differently than internal. Just go to the "script" tab, select the .js file from the drop-down list and set a breakpoint.