Facebook login widget's button fails to resize

Hi,
I am using the Ultimate Facebook plugin with the Buddypress Social Theme.

My left widget bar contains the Facebook login widget. You can see the page on this link.

I have noticed that suddenly, the widget stopped showing on Chrome or IE:

1. On Chrome, the login button isn't shown anymore, there is a blue boarder line there instead. After 45 seconds, my console shows this error message: "fb:login_button failed to resize in 45s" (called by app.js::49).

2. On IE, first shows the 'Facebook Login Button' text. Then the item totally disappears (although it does succeed occasionally, once in a few page refreshes). The console shows: "LOG: fb:login_button failed to resize in 45s".

The login widget still works as expected on Firefox.

Any idea what may have caused this?
Please advice,
Roei.