Bug or problem interacting with Upload path

I've recently moved from Drupal 5 to Drupal 6 where I had upload path (wich moves uploaded files to unique folders for each node) and workflow working perfectly together.

Now, I'm having a problem. If I edit the nodes and change their workflow status, everything is right. But if I go to workflow tab, I get this error:

Cannot use object of type stdClass as array in /home/xxx/www/sites/all/modules/uploadpath/uploadpath.module on line 36

I've also reported this issue in upload path forum: #610686: PHP error when trying to change node's workflow status.

Thanks in advance.