diff -r 6da1a12084a9 -r 92e8e5aaacde src/cm/media/js/client/c_addcomment_form.js
--- a/src/cm/media/js/client/c_addcomment_form.js	Tue Nov 05 18:29:29 2013 +0100
+++ b/src/cm/media/js/client/c_addcomment_form.js	Wed Nov 06 19:05:09 2013 +0100
@@ -31,6 +31,7 @@
   var overlayHtml = getHtml(gICommentForm) ;
   
   var width = gLayout.getTopICommentsWidth() ;
+  width += gLayout.iCommentsRequiredThreadPadding (); // SID: use max available space as there is no indentation on that box
   
   var overlay = new CY.Overlay( {
     zIndex :3,