Update warning: "Some of the pending updates cannot be applied because their dependencies were not met." Followed by "No pending updates." I inherited a site from a previous webmaster (who doesn't seem to have known what he what doing) last month and I have been trying to fix it up since then, but one pesky update issue won't go away. Whenever I run update.php, it goes through halfway and then stops with the following messages:

✓ Verify requirements(done)
✓ Overview(done)
▶ Review updates(active)

Warning message

Some of the pending updates cannot be applied because their dependencies were not met.

Status message

No pending updates.

• Front page
• Administration pages

I've been getting this error message for some time now whenever I run update. Some searching revealed that uninstalling and reinstalling the affected module might fix the error, but I can't figure out where it is coming from, or which module could be causing it. Is there any way to find out which module is causing this error without uninstalling and re-installing every single module on the site?
Just in case someone else finds this ... I added a watchdog line to the function update_script_selection_form($form, &amp;$form_state) in update.php.

foreach ($updates as $module =&gt; $update) {
  if (!isset($update['start'])) {
    $form['start'][$module] = array(
      '#type' =&gt; 'item',
      '#title' =&gt; $module . ' module',
      '#markup'  =&gt; $update['warning'],
      '#prefix' =&gt; '&lt;div class="messages warning"&gt;',
      '#suffix' =&gt; '&lt;/div&gt;',
    );
    watchdog('update','NO START: '.$module);
    $incompatible_updates_exist = TRUE;

    ...


It was XML sitemap causing the problems on a D6->D7 upgrade, and I ended up having to delete its tables manually before it would uninstall.