[fxwoody]

Nice! I'm using it and it works A1 with the IFrame.
Tho, i didn't put it under the control as it's to low, i switch it in my posbit-legacy under Icons&title

			<!-- icon and title -->
			<h3 class="threadtitle">
     <!---facebook-button--->
<if condition="$post[postcount] == 1"><iframe src="http://www.facebook.com/plugins/like.php?href=http://www.yoursite.com/showthread.php$session[sessionurl]?p=$post[postid]&amp;layout=button_count&amp;show_faces=true&amp;width=&amp;action=like&amp;colorscheme=light" 
scrolling="no" frameborder="0" allowTransparency="true" style="border:none; overflow:hidden; width:100px; height:20px"></iframe></if>
     <!---/facebook-button--->
				<if condition="$show['messageicon']"><img class="inlineimg" src="$post[iconpath]" alt="$post[icontitle]" border="0" /></if>

Better like this i think