[CM8.4.1.1204]The class column cannot be edited.

1Create one table
CREATE TABLE "a1"
CLASS ATTRIBUTE(
"d" date DEFAULT DATE'02/05/2012' NOT NULL
)
(
"i" integer DEFAULT 2 UNIQUE,
"c" character(10) DEFAULT '3 ' NOT NULL
);

2 choose column d

Actual result
1 Cannot edit the column .
2 When we change the default of class attribute, it cannot change
Now the sql is"ALTER TABLE "a1" ALTER CLASS "d" SET DEFAULT DATE'02/05/2012';"
It should be　＂ALTER TABLE "a1" alter class attribute "d" SET DEFAULT date'02/05/2012';＂