Different sort order

I'm wondering why the sort order on these two servers behaves differently.
The only difference I can see is that one is using a 32.bits Ubuntu and
the other is on 64bits versions of Ubuntu.
But why this difference ?

Thanks,
 Poul


mydb=# select * from test order by felt1;
 felt1
--------
 test1
 test_1
 test2
 test_2
 test3
 test_3
(6 rows)

mydb=# \encoding
UTF8
mydb=# select version();

version
------------------------------------------------------------------------------------------------------------
 PostgreSQL 8.1.9 on i486-pc-linux-gnu, compiled by GCC gcc-4.0.gcc-opt
(GCC) 4.0.3 (Ubuntu 4.0.3-1ubuntu5)


mydb=# select * from test order by felt1;
 felt1
--------
 test1
 test2
 test3
 test_1
 test_2
 test_3
(6 rows)

mydb=# \encoding
UTF8
mydb=# select version();

version
--------------------------------------------------------------------------------------------------------------
 PostgreSQL 8.1.9 on x86_64-pc-linux-gnu, compiled by GCC
gcc-4.0.gcc-opt (GCC) 4.0.3 (Ubuntu 4.0.3-1ubuntu5)
(1 row)