Hmm.. strange. Testing with a few Facebook accounts (on your site), I didn't initially see the "Not you" link.. I see "Change":
I believe I'm seeing that because I have multiple Facebook Pages and other things that I can 'change' too. I finally tested with a bare Facebook account and can see the "Not you" text and the results you describe. I'm honestly not sure what's going on with that.
This isn't something we'll be able to fix, as JFBConnect doesn't have control over those links. That's created completely by Facebook. From another quick test on their own creation tool, I'm seeing the same results:
developers.facebook.com/docs/plugins/comments/
Can you try and see if you have the problem there as well? If so, we can submit it as a bug to Facebook.
Thanks,
Alex