text type has no default operator class for GIN?

CREATE INDEX "ufile_name_search" ON "public"."uploadtree" USING GIN
("ufile_name");

ERROR: data type text has no default operator class for access method
"gin"
HINT: You must specify an operator class for the index or define a
default operator class for the data type.

This is on a new 8.3 install.
Why is this happening? Isn't creating a GIN index on a text type a
common thing to do?

I'm not seeing any mention of this in 8.3.7 docs cha 12 (Full Text
Search).

Do I really have to CREATE OPERATOR CLASS to make this work?
I see http://www.postgresql.org/docs/8.3/interactive/sql-createopclass.html

many thanks,
bob