Unwanted cascade delete by Doctrine2 - doctrine-orm

Question

I am working on a product catalog, and have two entities, PcatSalesItem and PcatCategory with a many-to-many relationship between them. If I delete a category, and there are still sales items associated with it, I want an exception to be thrown, I do NOT want cascading delete. On the RDBMS level (PostgreSQL), in the join table, I have set the foreign keys to "ON DELETE RESTRICT". However, when I delete a category that has sales items, Doctrine does a cascading delete. Nowhere have I specified cascade=remove to Doctrine!
Here are the entities:
/**
* PcatSalesItem
*
* #ORM\Table(name="pcat_sales_item")
* #ORM\Entity
* #Gedmo\Loggable(logEntryClass="Qi\Bss\BaseBundle\Entity\Business\LogEntryBusiness")
*/
class PcatSalesItem
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer", nullable=false)
* #ORM\Id
* #ORM\GeneratedValue(strategy="SEQUENCE")
* #ORM\SequenceGenerator(sequenceName="pcat_sales_item_id_seq", allocationSize=1, initialValue=1)
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="name", type="string", length=64, nullable=false)
* #Gedmo\Versioned
*/
private $name;
/**
* #var string
*
* #ORM\Column(name="description", type="text", nullable=true)
* #Gedmo\Versioned
*/
private $description;
/**
* #var array $categories
*
* #ORM\ManyToMany(targetEntity="PcatCategory")
* #ORM\JoinTable(name="pcat_category_x_sales_item",
* joinColumns={#ORM\JoinColumn(name="sales_item_id", referencedColumnName="id", onDelete="RESTRICT")},
* inverseJoinColumns={#ORM\JoinColumn(name="category_id", referencedColumnName="id", onDelete="RESTRICT")}
* )
*/
private $categories;
...
}
/**
* PcatCategory
*
* #ORM\Table(name="pcat_category")
* #ORM\Entity
* #Gedmo\Loggable(logEntryClass="Qi\Bss\BaseBundle\Entity\Business\LogEntryBusiness")
*/
class PcatCategory
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer", nullable=false)
* #ORM\Id
* #ORM\GeneratedValue(strategy="SEQUENCE")
* #ORM\SequenceGenerator(sequenceName="pcat_category_id_seq", allocationSize=1, initialValue=1)
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="name", type="string", length=64, nullable=false)
* #Gedmo\Versioned
*/
private $name;
/**
* #var array $salesItems
*
* #ORM\ManyToMany(targetEntity="PcatSalesItem")
* #ORM\JoinTable(name="pcat_category_x_sales_item",
* joinColumns={#ORM\JoinColumn(name="category_id", referencedColumnName="id", onDelete="RESTRICT")},
* inverseJoinColumns={#ORM\JoinColumn(name="sales_item_id", referencedColumnName="id", onDelete="RESTRICT")}
* )
*/
private $salesItems;
....
}
Here is the code I use to delete a category:
$em = $this->getDoctrine()->getManager();
$cat = $em->getRepository('QiBssBaseBundle:PcatCategory')->find(15);
$em->remove($cat);
$em->flush();
Any help will be greatly appreciated!