Right now I have this simple test form:
{exp:channel:form channel="data" category="6" status="Closed" return="contact/thanks" }
{/exp:channel:form}{exp:channel:form channel="data" category="6" status="Closed" return="contact/thanks" }
<input name="title" type="text">
<input type="submit" value="Submit">
{/exp:channel:form}
The data is submitted but it doesn't set the status or the category. Maybe I am misunderstanding the documentation on how this should work.