In pgAdmin V 1.4.3(Jul 19 2006)
1. Select DB Server
2. Select DB:your_DB_with_PK_in_any_table
3. Select Schemas:public
4. Select Tables:table_with_PK
5. Select Constraints:some_pk
6. Highlight 'some_pk'
7. Press right button on mouse during select 'some_pk'
8. Press 'Maintenance'
9. Select REINDEX and press 'OK'
and receive 'ERROR: syntax error at or near "PRIMARY" at character 9'
or see serverlog
----------------------
ERROR: syntax error at or near "PRIMARY" at character 9
STATEMENT: REINDEX PRIMARY KEY some_pk
------------------------------
Best regards,Alexander Kirpa