[Owncloud] PostgreSQL database error after upgrade from 4.8 to 5.0.9

[owncloud_mailing_list at status.e4ward.com]

Hello all.

I'm using a PostgreSQL database with owncloud, which is working great with Owncloud 4.8. However, I just tried to update to Owncloud 5.0.9 and although it said it updated successfully, whenever I try to visit a folder in my files, the page goes blank white and the error in my admin log says:

SQLSTATE[23505]: Unique violation: 7 ERROR: duplicate key value violates unique constraint "oc_filecache_pkey" DETAIL: Key (fileid)=(1) already exists. at /var/www/<domain>/lib/db.php#1031

Then when I visit my files again that directory I tried to visit has a size of zero and I still can't visit it. Does this mean anything to anyone? I need to keep Owncloud at 4.8 until I figure out a safe way to upgrade.

Thanks for your help!

Kyle