problem with inserting lead via api

problem with inserting lead via api

I am following the instructions given here...  
http://www.zoho.com/crm/help/api/insertrecords.html

I am a little confused because this document says to post the parameters...  but some of the examples show urls with query strings feeding the parameters.  Which parts of the request go into the body and which go into the querystring specifically?

at the moment i am trying to post all the parameters to body with the required fields... here is the request (censoring my authtoken):

newFormat=1&authtoken[CENSORED]&scope=crmapi&xmlData=%3CLeads%3E%3Crow%20no%3D%221%22%3E%3CFL%20val%3D%22Lead%20Source%22%3EWeb%20Download%3C%2FFL%3E%3CFL%20val%3D%22First%20Name%22%3ETest%3C%2FFL%3E%3CFL%20val%3D%22Last%20Name%22%3EUser%3C%2FFL%3E%3CFL%20val%3D%22Email%22%3Etesting%40testing.com%3C%2FFL%3E%3CFL%20val%3D%22Phone%22%3E1234567890%3C%2FFL%3E%3C%2Frow%3E%3C%2FLeads%3E

the data is urlencoded and I am specifying that in the header...  

what I am getting back is:
<response><error><code>4834</code><message>Invalid Ticket Id</message></error></response>

which is further confusing because i'm not using a ticket id...  

please help?