--- pyrrd/backend/external.py
+++ pyrrd/backend/external.py
@@ -264,7 +264,7 @@
         data += [unicode(x) for x in obj.rra]
         return (obj.filename, params + data)
 
-    if function == 'update':
+    elif function == 'update':
         validParams = ['template']
         params = common.buildParameters(obj, validParams)
         FIRST_VALUE = 0
@@ -277,15 +277,15 @@
             data = [data for data, nil in obj.values]
         return (obj.filename, params + data)
 
-    if function == 'fetch':
+    elif function == 'fetch':
         validParams = ['resolution', 'start', 'end']
         params = common.buildParameters(obj, validParams)
-        return (obj.filename, obj.cf, params)
+        return (obj.filename, [obj.cf] + params)
 
-    if function == 'info':
+    elif function == 'info':
         return (obj.filename, obj)
 
-    if function == 'graph':
+    elif function == 'graph':
         validParams = ['start', 'end', 'step', 'title',
             'vertical_label', 'width', 'height', 'only_graph',
             'upper_limit', 'lower_limit', 'rigid', 'alt_autoscale',