Search SQL error

Received this error once when clicking the following link on our site:

http://www.hairlosstalk.com/interact/search.php?search_id=egosearch

(basically the link that says "View your Active Topics"

General Error
SQL ERROR [ mysql4 ]

Duplicate entry '88c92691a75a15137f254a6c1597a0ea' for key 1 [1062]

SQL

INSERT INTO phpbb_search_results (search_key, search_time, search_keywords, search_authors) VALUES ('88c92691a75a15137f254a6c1597a0ea', 1215359433, '', ' 1636 ')

BACKTRACE

FILE: includes/db/mysql.php
LINE: 158
CALL: dbal_mysql->sql_error()

FILE: includes/search/search.php
LINE: 194
CALL: dbal_mysql->sql_query()

FILE: includes/search/fulltext_mysql.php
LINE: 633
CALL: fulltext_mysql->save_ids()

FILE: search.php
LINE: 423
CALL: fulltext_mysql->author_search()