a problem with get_where

[eluser]edhrx[/eluser]
Hi
this code
$query = $this->db->get_where('mem_sys_views', array('mode' => $mode,
'action' => $action));

Gives me this
Error Number: 1054

Unknown column 'form_id' in 'where clause'

SELECT * FROM (`mem_sys_views`) WHERE `form_id` = 'bfcebbbd76ff508773d7a974e308bae5' AND `mode` = 'member' AND `action` = 'edit'
Note form_id is not in the 'where' array

I'm guessing (at the moment)it comes from a previous call to where() or get_where()
Do I somehow need to 'clear' the where clause before creating another

I'm on the latest version of CI

best wishe Ed