Error Messages!?

Dear All,

I have recently started working on psql, I am experiencing an error, and
I am unable to find any documentation on Psql's error messages.

The problem is as follows;

If I say :

"DELETE FROM PERMISSION WHERE PERMISSIONNO = 1176;"
I should delete that permission :- I Know it exists.

However, I am recieving the error message;
"ERROR:  check_foreign_key: invalid number of arguments 10 for 3
references"

The primary key for the table is PERMISSIONNO, there are no forien keys.

Below is an Entiry Relationship Diagram showing the relation from
permission to other tables.


[agreementpermission] -- < [permission] >--- [PermissionImageDate]

|
|

/|\
/|\

[Agreement]
[Imagedate]

In Permission, primary key is permissionno.

In agreementpermission, (link table) it has forien key permissionno & forein key agreementno.

Agreement has primary key agreement no.

Any Ideas, why the error message is occuring? I would love to hear from anyone who has any ideas.

I know I haven't explained this very well!

Best Regards

Luke Tudor.