Sorting problem

Hi all,
I have a problem sorting varchar fields.
I will explain the problem with a simple example:

this query
select '##10' as sortfield
union
select '###1' as sortfield
order by sortfield
produces this correct output:
'###1'
'##10'

but this one

select '##10############--------####79909999' as sortfield
union
select '###1############--------####79909999' as sortfield
order by sortfield
produces this wrong output:
'##10############--------####79909999'
'###1############--------####79909999'

I'm using postgresql 7.4.3 on Suse Linux 9.1.
I created my db using: initdb --pgdata=../data/ --encoding=LATIN1
--lc-collate=it_IT --lc-ctype=it_IT

Any suggestion?
Tia
Ruggero