Forum OpenACS Development: Cant Delete a package in openacs5.1

but

I am getiing the following error

==================================

Deleting package instance 885
The database returned the following error message

Database operation "0or1row" failed (exception NSDB, "Query was not a statement returning rows.") ERROR: acs_objects_context_id_fk referential integrity violation - key in acs_objects still referenced from acs_objects SQL: select apm_package__delete('885');

====================================

I tried the Forums application and page application
and my own application and other

all are getting the same errour

I went through the pgsql function

--- select apm_package__delete(int4)

in the script the code written for

1)deleteing the row from apm_packages where ppackage_id=XXX

and

2)deleting the row from apm_applications where application_id=XXX

XXX=package_id

it has other stuff also
*****************
I deleted the above two rows manually

then

I could uninstall

But

I could not find the problem --- why it is getting problem while running -----select apm_package__delete(int4)

thnks