Permission denied for create table

Hello, I'm doing a workshop for my students and I'm teaching them how to
create tables in Postgres.

So I created a database for every student, but I'm facing the following
problem:

sql073751=> CREATE TABLE emp1 (id int);

CREATE TABLE

sql073751=> SELECT * into emp2 from emp;

ERROR: emp: permission denied

sql073751=> CREATE TABLE emp3 as SELECT * from emp;

ERROR: emp: permission denied

Creating a normal table works fine, but creating a table with subqueries is
giving me "permission denied"

Anyone got a clue?

P.S. I'm working on PostgreSQL 7.3.2

Thx

Pascal