Need help in programatically creating form with array of textfields rendered in a table

Hi,

After hours of searching in forums and trying different things, i finally came to think that the best is to ask here about my problem.
I'm a beginner in drupal API but i'm making programs in my professional life since many years

I want to create an edit form containing values from different request in database and that a user could change through the form. The idea is to show it in a table form.

Something that would look like :

row1  | Label1        | textfield1  | textfield2     | label2    |
row2  | Label1        | textfield1  | textfield2     | label2    |
...

Problème is #defaut_value from textfield is not shown and when i enter a value in the textfield, i cannot get #value as it is empty

If i use #value in code, values are visible but user input does not change #value when i get them from $form_state

Problem seems linked to the fact that my fields are in an array rendered to a table.
When i use textfields in the form, it is ok.

I have the problem with textfields or textarea inside a table. No problem with items , their default_value is well rendered.

Here are some parts of my code , i changed some names as i don't want them to be shown here :

Menu to define an access to my form

/**
 * Implements hook_menu().
 */
function mymodule_menu() {
  $items['admin/mymodule/%itemid/edit'] = array(
    'title' => 'Edit',
    'type' => MENU_LOCAL_TASK,
    'page callback' => 'drupal_get_form',
    'page arguments' => array('mymodule_edit_form', 3),
    'access arguments' => array('mymodule_administer'),
    'weight' => 5,
    'context' => MENU_CONTEXT_PAGE | MENU_CONTEXT_INLINE,
  );
  return $items;

}

Then my function to build my form

/**
* Edit facture form
*/
function mymodule_edit_form($form, &$form_state, $mydata) {

  //Item id
  $form['myitem_id'] = array(
    '#type' => 'hidden',
    '#default_value' => $mydata->myitem_id,
  );

  $form['destination'] = array(
    '#type' => 'hidden',
    '#value' => drupal_get_destination(),
  );

  //Table header
  $mytable_row_headers = array();
  $mytable_row_headers[] = array('data' => t('item1'), 'field' => 'item1');
  $mytable_row_headers[] = array('data' => t('item2'), 'field' => 'item2');
  $mytable_row_headers[] = array('data' => t('item3'), 'field' => 'item3');
  $mytable_row_headers[] = array('data' => t('item4'), 'field' => 'item4');  

  //Table data
  $mytable_rows_data = array();
  foreach($mydata->rows_data as one_row_data) {
     $mytable_rows_data[] = mymodule_build_row($one_row_data);
  }
  
  $form['fact_rows'] = array(
    '#prefix' => '<div id"my_rows">',
    '#suffix' => '</div>',
    '#tree' => TRUE,
    '#theme' => 'table',
    '#header' => $mytable_row_headers,
    '#rows' => $mytable_rows_data,
    '#element_validate' => array('mymodule_rows_validate'),
  );
  
  //One test textfield to check if #default_value is working
  $form['textfield_test'] = array(
      '#type' => 'textfield',
      '#default_value' => 'Test',
      '#element_validate' => array('mymodule_textfield_validate'),
      )
  ;

  //Submit button
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
  );

  field_attach_form('mymodule', $mydata, $form, $form_state);

  return $form;
}



function mymodule_build_row($one_row_data) {

  $one_row['item1']    = array('data' => array(
                                 '#type' => 'item' ,
                                 '#markup' => $one_row_data['item1_data'],
                                ));
  $one_row['item2'] = array('data'  => array(
                                 '#type'      => 'textfield',								 
                                 '#default_value'     => $one_row_data['item2_data']),
                                 '#size' =>10,                                 
                                 '#required' => TRUE,
                                 '#field_suffix' => => $one_row_data['item2_suffix']),
                                ));
  $one_row['item3']   = array('data' => array(
                                 '#type' => 'textfield',                                      
                                 '#default_value'  => $one_row_data['item3_data']),
                                 '#size' => 3,
                                 '#required' => TRUE,
                                ));
  $one_row['item4']     = array('data' => array(
                                '#type' => 'item',
                                '#markup' => => $one_row_data['item4_data']),                                
                          ));
  return $one_row;

Table array is rendered fine, and item1 / item4 values are visible.
For item 3/4 i get empty textfields.
After submission i don't get any value from #value on my item in $form_state, and rendered page does not keep entered values

If i use #value instead of #default_values, i have textfields with values visible but in validation when i get #value from $form_state i have original values and not entered values.
After submission page is displayed again with old values.

For a textfield not in a table, it is working as i expect.

Thanks for your help.

Ludovic