set datestyle to European PROBLEM

I have the defaul installation of postgres 7.0.3 and on another machine
7.1.2 on redhat 7.1

I cannont get the date in correct form:

dbme=# select data_ar from equipment limit 5; data_ar   
------------2001-11-052001-05-172001-05-282001-05-282001-05-22
(5 rows)

then:

dbme=# set datestyle to European;
SET VARIABLE

dbme=# select data_ar from equipment limit 5; data_ar
------------2001-11-052001-05-172001-05-282001-05-282001-05-22
(5 rows)

Is this a bug ?

I think i should get dd-mm-yyy date format and not yyyy-mm-dd 



Is postgres using ISO date format as default ?

Thanks

Alex