Very odd order by behavior

FreeBSD 4.2, PostgreSQL 7.0.3

The attached file is the schema and data to the app_degrees table. Now check
this out :

select * from app_degrees gives (expected) :
degree_id |  abbr  |               description
-----------+--------+------------------------------------------     1818 | ACC    | Accounting [ACC]     1819 | ACD
|Acoustics [ACD]     1820 | ADV    | Advertising [ADV]
 

select * from app_degrees order by abbr ASC gives :
degree_id |  abbr  |               description
-----------+--------+------------------------------------------     1818 | ACC    | Accounting [ACC]     1818 | ACC
|Accounting [ACC]     1819 | ACD    | Acoustics [ACD]     1819 | ACD    | Acoustics [ACD]     1820 | ADV    |
Advertising[ADV]     1820 | ADV    | Advertising [ADV]
 

Either I'm seeing double or something isn't right here :-)

Thanks for any insights.

-Mitch