IceWeasel crash my debian laptop

["jeffry s" <jeffry@bayau.com>]

i am using my laptop with PHP 4+ and mysql 5+, everything start to be
weird after i implement my costume sessions (storing in database).
i only use one database connection for the whole website. 
what i mean is, the session and every query connect to mysqlserver using the same user.

I am not sure if it is because of the sessions. but it happen after i use costume sessions.

if i make a SQL query with non existant column name eg: noe

SELECT * FROM test WHERE noe=1;

Suddenly,
if i use top to monitor process on my laptop i saw the processor usage
for the mysqld and firefox-bin(iceweasel) increasing.
Icewasel will continue to consume processor usage to 100% and memory up to 80% all the time.

Worst still, the mouse, keyboard do not work anymore. My laptop very-very slow until i cannot move my mouse cursor at all..

there is no way i can go except turn off the laptop power. 

I
don't know what the problem is this. but, i think there is something to
do with the sessions. And it related to PHP or may be problem with
Iceweasel.

i am using debian unstable. last updated march 2007..