Facebook like button not working

Hi:
Clicking on the K2 facebook like button is causing a modal box that is cut off at the bottom, with the result that the pop-up is frozen on the screen. Any way to fix this?
The url is http://www.provencalbistro.com/news/ite ... fixe-lunch

imageedit_2_2039559077.png

Hi,

Try this in override:

.fb_iframe_widget iframe {
max-width: 1000px!important; overflow: visible
}

good luck!

Thank you Stefje for your suggestion!
Unfortunately, it is not fixing the problem. It looks more like a z-index issue, but I can not find how to change it.
I have attached another screenshot because the first one was maybe not clear. This bug happens when (i) you first "like" the K2 article; then (ii) you go back and click the "like" button again. There is a form that is partly covered by the module below.

Screenshot 2015-01-30 12.26.372.png