Glad to hear the social toolbar is working well for you. So far, that features been well received (even if our documentation for it isn't quite up to snuff yet).
As for why it's not showing, I'm honestly clueless here. I've never heard of this issue, and it's definitely specific to that one computer (and not IP address), which makes it even more confusing.
There's obviously something different about that computer, but I'm not sure what it would be. There's definitely nothing that JFBConnect should be doing to exclude one specific computer. There are ways to load each browser without addons.. for IE, it's in the Start -> Accessories -> System Tools. I don't remember for other browsers off hand.
I guess one final suggestion is to try the "Private Mode" of your browsers, just as a chance.. though I doubt that will do it.
Definitely keep me posted if you find anything out as I'm curious, and I'll let you know if we have any other ideas, but this one is new to us...
Thanks,
Alex