7.4beta1, Error in dumpall from 7.3.4 since CASCADE could not be used in REVOKE in 7.3.4

The following table was created in PostgreSQL 7.3.4

create table dummy_groupmember_is_admin
(bemerkung varchar(20));
GRANT SELECT, UPDATE, INSERT ON dummy_groupmember_is_admin TO GROUP admin;
REVOKE ALL ON dummy_groupmember_is_admin FROM cb,postgres;

If I read in the dumpall from the PostgreSQL 7.3.4 database with PostgreSQL
7.4beta1 I get an error and the Hint that I should use CASCADE.
The error line number points to:
REVOKE ALL ON dummy_groupmember_is_admin FROM cb,postgres;

But if I want to use CASCADE in PostgreSQL 7.3.4, I get a parse error.

Indeed, the manual of 7.3.4 does only mention CASCADE with REVOKE in a note
about SQL-92 compatibility, while the manual from 7.4beta1 shows that CASCADE
is an optional part of the REVOKE command.

Regards
Christoph Becker