diff --git a/gen/__init__.py b/gen/__init__.py
index f7f3091..ec5dd56 100644
--- a/gen/__init__.py
+++ b/gen/__init__.py
@@ -1898,7 +1898,8 @@ class Ref(Type):
                     self.back.unlinkObject(tool.getObject(refs[i]), obj)
                 i -= 1
         # Link new objects
-        self.linkObject(obj, objects)
+        if objects:
+            self.linkObject(obj, objects)
 
     def clone(self, forTool=True):
         '''Produces a clone of myself.'''
diff --git a/gen/ui/appy.css b/gen/ui/appy.css
index 35907a3..8deaadf 100644
--- a/gen/ui/appy.css
+++ b/gen/ui/appy.css
@@ -58,7 +58,7 @@ img {border: 0}
                 margin: 0.4em 0 0.2em 0; }
 .phase { border-style: dashed; border-width: thin; padding: 0 0.6em 5px 1em;}
 .phaseSelected { background-color: #F4F5F6; }
-.content { padding: 14px 3px 9px 15px;}
+.content { padding: 14px 14px 9px 15px;}
 .grey { display: none; position: absolute; left: 0px; top: 0px;
         background:grey; opacity:0.5; -moz-opacity:0.5; -khtml-opacity:0.5;
         filter:alpha(Opacity=50);}
@@ -81,8 +81,9 @@ img {border: 0}
             border-top: 1px solid #8CACBB;border-bottom: 1px solid #8CACBB; }
 .section2 { font-size: 110%; font-style: italic; margin: 0.45em 0em 0.2em 0;
             border-bottom: 2px solid grey; }
-.section3 { font-size: 100%; font-style: italic; margin: 0.45em 0em 0.1em 0;
-            background-color: #F4F5F6; text-align: center; color: grey; }
+.section3 { font-size: 100%; font-style: italic; font-weight: bold;
+            margin: 0.45em 0em 0.1em 0; background-color: #F4F5F6;
+            text-align: center; color: grey; }
 .odd { background-color: white; }
 .even { background-color: #F4F5F6; }
 .summary {margin-bottom: 5px;}
diff --git a/gen/ui/widgets/ref.pt b/gen/ui/widgets/ref.pt
index 0d4a7c2..9d8941e 100644
--- a/gen/ui/widgets/ref.pt
+++ b/gen/ui/widgets/ref.pt
@@ -241,7 +241,7 @@
 <select tal:attributes="name name;
                         size python: test(isMultiple, widget['height'], '');
                         multiple python: test(isMultiple, 'multiple', '')">
-  <option tal:condition="not: isMultiple" tal:content="python: _('choose_a_value')"></option>
+  <option value="" tal:condition="not: isMultiple" tal:content="python: _('choose_a_value')"></option>
   <tal:ref repeat="refObj allObjects">
     <option tal:define="uid python: contextObj.getReferenceUid(refObj)"
             tal:content="python: contextObj.getReferenceLabel(name, refObj)"