Hi Tammy,
Sorry, meant to reply sooner. Which version of OACS and PG are you using? I seem to remember having this same problem in a previous version of OACS and solving it the way you did: nulling out the live/latest revision of the content item before deleting it. Or maybe I removed all the associated revisions before calling content_item__delete. I honestly can't remember, but you get the idea.
For the record, on my test OACS 4.6.3 (final)/PG 7.2.4 install, everything seems to work fine. I created a content_item with 3 revisions, and was able to successfully delete it without having to do anything special:
# select live_revision, latest_revision from cr_items where item_id = 383;
live_revision | latest_revision
---------------+-----------------
385 | 386
(1 row)
# select content_item__delete(383);
NOTICE: Deleting symlinks...
NOTICE: Unscheduling item...
NOTICE: Deleting associated revisions...
NOTICE: Deleting associated item templates...
NOTICE: Deleting item relationships...
NOTICE: Deleting child relationships...
NOTICE: Deleting parent relationships...
NOTICE: Deleting associated permissions...
NOTICE: Deleting keyword associations...
NOTICE: Deleting associated comments...
NOTICE: Deleting content item...
content_item__delete
----------------------
0
(1 row)
# select * from cr_items where item_id = 383;
(0 rows)
