observe_form doesn't seem to work from inside of a table

If I do observe_form as below, the ajax call never occurs, but If I
remove the table it works fine.
This is just a test to troubleshoot as I had narrowed down my problem
to this, I actually wanted a form per row of the table:

<table>
<tr>

<% form_tag({:controller => 'sheet_entry', :action =>
'pass_input'}, :id => 'frmx1') do %>
   <td> hey <%= text_field_tag 'xx', 'xxx' %> </td>

<%= observe_form('frmx1', :url => {:action => 'ajx_form_changed'},
                  :frequency => 0.5)%>

<% end %>

</tr>
</table>

is not allowed between and or between and . It is a major inconvenience but that is the way it is.