How to use delete cascade when joins are the same table

[Joshua Savage]

I have a situation where I have 2 tables - tags and association. I use it to manage relationships between tags.

Tag Table
------
id
phrase

Association Table
---------
tag_id -> references Tag table
parent_id -> also references Tag table
...extra fields for other stuff...

I need the association entries related to a tag to be removed when a tag is deleted. However using ondelete cascade as:

CONSTRAINT `association_parent_id_tag_id` FOREIGN KEY (`parent_id`) REFERENCES `tag` (`id`) ON DELETE CASCADE,
CONSTRAINT `association_tag_id_tag_id` FOREIGN KEY (`tag_id`) REFERENCES `tag` (`id`) ON DELETE CASCADE

does not work - I suppose there is some kind of circular reference issue. I get errors like: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails...

I currently have to delete the associations related to the tag as a separate act - how can I get mysql to manage these delete?

Thanks!