The following pieces of code fail in all of my projects:

$ca = new DataObjects_Categories;
$ca->get(<some id>);
$ca->deleteAll();

Where the class DataObjects_Categories is defined as:

class DataObjects_Categories extends DB_DataObject {

<... snip ...>

    function &getSubCategories() {
      $scs = new DataObjects_Sub_categories;
      $scs->ca_id = $this->id;
      $scs->find();
      return $scs;
    }

    function deleteAll() {
      DB_DataObject::debugLevel(1);

      $sc = $this->getSubCategories();
      while ($sc->fetch()) {
        $sc->delete();
      }
      $this->delete();

      DB_DataObject::debugLevel();
    }

<... snip ...>

}

The script, with debugLevel(1), returns:

*--*

__find 
sql QUERYSELECT * FROM sub_categories  WHERE  sub_categories.ca_id = 33   
query DONE QUERY
__find CHECK autofetchd 
__find DONE
fetchrow sub_categories DONE
sql QUERYDELETE FROM sub_categories  WHERE  sub_categories.id = 132
query DONE QUERY

Fatal error: Call to a member function on a non-object in pear/lib/php/DB/DataObject.php on line 385

*--*

There were three sub_categories in the database that should have been deleted during this execution.  However, the fetch() loop only gets executed once before the fatal error.  Two sub_categories and their parent category remain.

I believe the bug lies in the fetch() statement of:

  while ($sc->fetch()) {
    $sc->delete();
  }

where it appears to fail after the first loop.