dropped users appear as numbers in ACL

I have experienced this in the past with members of groups, but now with
relation ACLs. It goes like this:
Certain users are given specific permissions of different tables and
such.
The users are later dropped but reference to them remains in the ACL as
their former ID number.
When trying to revoke permissions on the number, it fails.
I noticed this with groups in the past and have become accustomed to
deleting these users from the groups before dropping them. Otherwise I
had to create dummy users with those IDs, go about cleaning things out
and then drop the dummy user.
Will I have to perform this same procedure for ACLs?
Are there any plans to handle these issues transparently when a user is
dropped?
--
Bill MacArthur
Webmaster
DHS Club