Is there a contradiction in the translation of the Bhūmija Sutta? The Bhūmija Sutta in the Nidanasamyutta of the Samyutta Nikaya appears to be a very important sutta for the Sri Lankan Mahavihara &amp; Buddhaghoṣa school that came to dominate south east Asian Buddhism. For example, it appears that from the Bhūmija Sutta comes the rationale for the translation of the Dependent Origination terms 'kāyasaṅkhāraṃ, vacīsaṅkhāraṃ &amp; cittasaṅkhāraṃ' as 'volitional or kamma formations' despite these terms being explicitly defined in a different manner in MN 44.

(Of note, monks such as Buddhadasa, Nanavira, Nanananda &amp; even a certain work by Thanissaro have used the MN 44 definitions in their explanations of Dependent Origination). 

The Bhūmija Sutta appears to begin by stating the Buddha does not teach as the "proponents of kamma" do, namely, maintaining that happiness and suffering are done by oneself or by another. 

Yet the common translations then appear to later show the Buddha explaining that: 


  "...on one’s own initiative (sāmaṃ), Ānanda, one generates (abhisaṅkharoti) that bodily volitional formation (kāyasaṅkhāraṃ) conditioned by which pleasure and pain arise
  internally...."


More questionable is the different terms 'kāya­sañ­ceta­nā' (as 'bodily volition') &amp; 'kāyasaṅkhāraṃ' (as 'bodily volitional formation') appear to be translated in essentially the same way, as follows:


  Ānanda, when there is the body, because of bodily volition (kāya­sañ­ceta­nā) pleasure and pain arise  internally...with ignorance as condition...Either on
  one’s own initiative, Ānanda one generates that bodily volitional
  formation (kāyasaṅkhāraṃ)...


Now it should be noted the suttas, such as AN 6.63, clearly state that: "volition is kamma" &amp; conform with the start of the  Bhūmija Sutta by starting happiness &amp; suffering are dependent on contact. 


  "Intention (volition), I tell you, is kamma. Intending, one does kamma by way of body, speech &amp; intellect....Contact is the cause by
  which kamma comes into play."


Therefore, is there a contradiction in the translation of the Bhūmija Sutta where the "proponents of kamma" are refuted yet essentially the same doctrine of 'self-generated-kamma' is translated as the doctrine of the Buddha?
There's no such contradiction. Karma can indeed be categorised as prompted and unprompted as in if it was instigated by another or not.

What's refuted here is a person or a third party being able to create pain, pleasure or neutral feelings at will. Feelings arise due to contact.

Ex: One cannot say "let there be pleasurable feeling at the ear" and make it arise, if there's no contact at the ear. Even if one performs the physical act of playing a song, if one is deaf, pleasurable hearing won't arise since there's no contact.