Secondary submit function for form input button
The problem with your code is the default value for the form field attributes. In the case of the "button" form field, these are the default values:


#name => 'op'
#button_type => 'submit'
#executes_submit_callback => FALSE
#ahah['event'] => 'mousedown'


Those are also the default values for Drupal 7.

If you want to use a submission callback for a button, then you need to change the form field definition to the following one:

$form['questions']['buttons'][$counter] = array(
  '#type' =&gt; 'button', 
  '#name' =&gt;'button_' . $counter, 
  '#value' =&gt; t('Remove'),
  '#executes_submit_callback' =&gt; TRUE,
  '#submit' =&gt; array('my_mod_remove_submit'),
);


As alternative, instead of using a "button" form field, you should use a "submit" form field.