Index: suds/bindings/document.py
===================================================================
--- suds/bindings/document.py	(revision 710)
+++ suds/bindings/document.py	(working copy)
@@ -60,6 +60,10 @@
             else:
                 value = kwargs.get(pd[0])
             n += 1
+            # XXX: Not sure if this goes here
+            if pd[2] and value is None:
+                # skip non-existing by-choice kwargs
+                continue
             p = self.mkparam(method, pd, value)
             if p is None:
                 continue
@@ -123,13 +127,7 @@
             for child, ancestry in resolved:
                 if child.isattr():
                     continue
-                if self.bychoice(ancestry):
-                    log.debug(
-                        '%s\ncontained by <choice/>, excluded as param for %s()',
-                        child,
-                        method.name)
-                    continue
-                result.append((child.name, child))
+                result.append((child.name, child, self.bychoice(ancestry)))
         return result
     
     def returned_types(self, method):
@@ -157,4 +155,4 @@
         for x in ancestry:
             if x.choice():
                 return True
-        return False
\ No newline at end of file
+        return False