I just updated to the current 6.x-2.x-dev via github from the -beta10 on drupal.org and lost the FB connect graphic in the login block, which effectively makes the module unusable.
I have followed all directions correctly (I believe) and added the appropriate FBML handlers in the tag of the page.tpl.php for my current theme (the giordani branch of marinelli).
*Feel free to merge with all the other browser-specific issues of this problem, but this problem is related to my updating to the current dev branch and runs across browsers. Thus, I thought it distinct enough to merit its own issue.*
Also, devs/maintainers: change "unable" to "enable" on the checkbox for "Fast Registration mode" on the "Appearance" tab in the settings. Unable and Enable are opposites and I believe you mean to write enable. ;-)