Refreshing a from in a Zone

Hi everyone,

I have form that basically displays couple of checkboxs that user can
select/deselect. Once he is made his choice he clicks a button and a form
is submited, zone is refreshed (include the form).

All of the data is nicely displayed but a second submissions throws the
error

Forms require that the request method be POST and that the t:formdata query
parameter have values.

Am I doing something wrong? Is my scenario possible?

Let me know if you need code samples

Cheers