[ic] transaction id comes back as missing on a prior_auth_capture

[interchange-users@icdevgroup.org (Aaron Hazelton)]

Hi All,

I am setting up a prior_auth_capture capability in a version 4.8.3
store for the UI, and thanks to the archives, it is going surprisingly
well.  I am getting back an error from AuthorizeNet though, that
the transaction ID field cannot be left blank.  I am stuck.  here's
what I have and the error I receive.  You will see that I even tried
manually entering a trans_id for debugging purposes and I still 
get this response.  the account is in TEST mode, and I am
wondering if it is working, but just *refusing* the trans_id.  there
seems to be no way to tell that unless someone has seen this
before.

[button form=transactions bold=1 text="[L]Charge Order [cgi order][/L]"]
	mv_nextpage=@@MV_PAGE@@
	order=[cgi code]
	mv_todo=return
	[charge route=authorizenet transaction=PRIOR_AUTH_CAPTURE
order_id=0212172046212810 amount='[loop-data transactions total_cost]'
auth_code='[loop-data transactions x_auth_code]']

    {
'x_auth_code' => "000000",
'x_trans_id' => "0",
'pop.error-message' => "A valid referenced transaction ID is required.",
'pop.order-id' => "0",
'MErrMsg' => "Authorizenet error: A valid referenced transaction ID is
required.. Please call in your order or try again.",
'x_response_subcode' => "2",
'MStatus' => "failure",
'x_response_reason_text' => "A valid referenced transaction ID is
required.",
'x_response_reason_code' => "33",
'pop.auth-code' => "000000",
'x_avs_code' => "P",
'pop.status' => "3",
'x_response_code' => "3",
'pop.avs_code' => "P",
}

Any Ideas??
--
Aaron