I use JFBConnect on different website without any issue, but in one 1.5 installation I experience big issue with static.ak.fbcdn.net that slows the page load to 20 sec. This happened from one day to the other without changes on the website structure... or at least I thinks so...
The website is www.spb24.it.
Any loading being done from static.ak.fbcdn.net is all in the browser itself, not from your server. That means it could be your computer that you're using, your ISP, or any of the network connections between you and Facebook.
Sometimes, the internet just has a bad day. Unfortunately, there's not much we could do to correct this in JFBConnect itself. Most connections to that URL are to load user avatars. So, if you're using something like the JFBCFan module, disable the "Show Avatars" option so that user profile pictures aren't loaded.
Beyond that, I'd recommend testing from other computers/network connections and see if you still run into issues. If so, let us know, and we'll gladly help how we can. As quick as the problem came though, it will probably go away as well.