phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('fdff792f9bc249679a7177c425e5eefb', -1, 1327742921, 1327742921, '266bb3f2', 0, 0, 0)

Line : 189
File : sessions.php