attachstream via control port, permission denied?

[Jon McLachlan]

Running, version 0.2.0.16-alpha, I am...

1) extend one new tunnel, of length 2 through (1st hop) OR w/ 
purpose=bridge, (2nd hop) OR w/ purpose=controller
Note, Tor indicates one built circuit of length 2:
250-circuit-status=50 BUILT $[some-hex-value],$[some-other-hex-value]
250 OK

2) connecting to Tor via privoxy with an http request,
Note, Tor indicates a stream-request (unattached):
250-stream-status=27 NEW 0 [some-ip]:[some-port]
250 OK

3)  Attempt to manually attach the stream to the circuit by sending via 
the controlPort (I've also noticed that it will not automatically attach 
the stream):

To Tor:  ATTACHSTREAM 27 50
 From Tor:  555 Connection is not managed by controller.

 From these, it almost seems like because the Tor controller did not 
init the stream, that the attach is rejected.  It doesn't seem like 
streams have purposes, but do they?  Might I need to set the purpose of 
the new stream to purpose=controller?  If this is not the case, maybe 
there is a way that the controller could init a special stream?

As always, any comments or advice would be most valuable and very much 
appreciated :)

Best Regards,
~Jon