table permissions II

I had similar problems, especially when granting DELETE permissions 
insert commands worked as intended. 
And I did not mess with any config files. 
Regards, Christoph 

> Hi everybody,
> I can't seem to figure this one out.
> I have a superuser root and a regular user oleg. I am trying to insert a
> new row in table Set, which references table Activity, being logged in
> as root. I get an error saying:
> activity: Permission denied.
> This is very weird because root has all the permissions on every table
> in the database. Even more strange is that as soon as I grant DELETE
> privilege to user oleg, the problem disappears and I can add a row to
> the Set table.
> Does anybody know how to solve this problem?
> Should I upgrade my PostgreSQL version? I am currently using v 7.1.2