sorting problem

I found some problem about the sorting when i switch to pg version 8.3.4

Table name : tt,

record list :

      item_code
----------------------
 VAAAA
 VBBBB
 VCCC
 (V)BBBB
 V.BBBB
 V.AAAAB
 V.AAAA
 .VAAAA
 VA.AAA
 (VBBBB
 V)BBBB
 (V)B.BBB
 (VB)BBB
(13 rows)

the result : select * from tt order by item_code;

      item_code
----------------------
 VAAAA
 .VAAAA
 V.AAAA
 VA.AAA
 V.AAAAB
 VBBBB
 (VBBBB
 (V)BBBB
 (V)B.BBB
 (VB)BBB
 V.BBBB
 V)BBBB
 VCCC
(13 rows)

the sort sequence like ignore the character '.' , '(', ')'. Is it a bug ?
It is no problem in old version !!!!