--- a/web/formwidgets.py	Mon Dec 21 20:26:30 2009 +0100
+++ b/web/formwidgets.py	Mon Dec 21 20:26:52 2009 +0100
@@ -65,6 +65,8 @@
     def process_field_data(self, form, field):
         posted = form._cw.form
         val = posted.get(field.input_name(form))
+        if isinstance(val, basestring):
+            val = val.strip() or None
         return val
 
     @deprecated('[3.6] use values_and_attributes')