There is a single case, in which Firebug creates additional network requests. This is to load the sources for a JavaScript file in case the browser cache and the
Net panel are disabled while the
Script panel is enabled. See
issue 7585.
Otherwise Firebug does not create network requests. And if it's disabled for a page it even doesn't use any ressources.
If I understand you well, you have a single page that consists of 2,000 files? If so, you should definitely try to reduce the number of requests.
Anyway, as a shot in the dark I'd say your requests may be caused by redirects. I suggest you try out your steps using a
new Firefox profile. If you still get this huge amount of requests, it's related to the page or the server*. If you get the expected number of requests, go back to your normal profile, disable all extensions and check again whether you see the correct amount of requests. If so, enable the extensions one by one and try it again after enabling each extension.
* I remember a case, in which a bug in a specific version of a ColdFusion server executed a script twice for a single request. (Though that's definitely an exceptional case.)
Sebastian