Does vDS 5.1 only use NetFlow version 10? Need version 5/9

I setup NetFlow on my vSphere 5.1 vDS but i have not been seeing anything in my Netflow Collectors which are the Splunk for NetFlow app and NFSEN/NFDUMP. I was just reading that with 5.1 it uses NetFlow version 10? is there a way to force it to use version 5 or 9? Most NetFlow collectors do not support version 10 so i find this rather strange and useless. If this is the case then my plans to gather NetFlow from my environment with the vDS internal traffic only option will not work.