Redundant data in postgres

[lynux]

Hye,

I'm quite new in postgres.I have 2 problems that i do not how to solve. Hope somebody can help me.

1. Although i put my zone field is unique, postgres sometimes redundant my
data automatically.E xample :
-----------------------------------
rundate | zone
-----------------------------------
01/30/2007 | #01
-----------------------------------
01/30/2007 | #01
-----------------------------------

2. Why does when i make a select statement like this
'select runndate,zone from tb_team_arch where rundate='30 January 2007' , postgres give me data like this
-----------------------------------
rundate | zone
-----------------------------------
01/30/2007 | #01
-----------------------------------
11/02/2007 | #01
-----------------------------------

This result make my system goes wrong.
I really hope somebody can help me
Thank you

[michaelb]

This is highly unlikely that Postgres would allow a duplicate data on a unique field.
Could you review the table definition?
If you're not sure you can post it here. If you don't have any management tools, then the easiest way to get the table schema and constraints is to open the psql session and enter this command:

\d table_name
-- or
\d+ table_name