Can't add event via ColdFusion

I'm trying to add an event via CF. I've done the proper call to get my
auth string. I then tried to post like so:

<cfhttp
url="http://www.google.com/calendar/feeds/rcamden@xxxxxxxxx/private/full";
method="post" result="result">
        <cfhttpparam type="header" name="Content-Type"
value="application/atom+xml">
        <cfhttpparam type="header" name="Authorization" value="GoogleLogin
auth=#authcode#">
        <cfhttpparam type="formField" name="entry" value="#myxml#">
</cfhttp>

The Google docs says I should send the event xml, but it doesn't say
how I should name the form field, so I tried entry, content, etc, but
it didn't work.

When I examine the result, I get a status 200 and no error. The content
of the result appears to be my XML feed of events. The event is never
added though.