How can i enable automatic path creating for all nodes? In Drupal 7.12 i use pathauto, cleanurls, transliteration, i18n.

When i edit one node i saw that, "Generate automatic URL alias" in unchecked.
Then i checked other nodes and saw that for all type of nodes it became unchecked.

I'm pretty sure that it was checked until last week.

The last modifications i made:
I updated Pathauto module, installed Transliteration, installed Debug Cron module.

So, how can i re-enable this checkbox in node settings page automatically ?

(Of course i can i that manually, by editing every node, and checking the check-box)

Thank you very much for your help.
If you have Pathauto installed, it will generate path aliases for your nodes. It unchecks the box when there's already a path alias, letting you know that it won't change the alias if you change the content. You can change this behavior with the 'Update action' setting here: /admin/config/search/path/settings