Changing max_allowed_packet in MySQL 3.23

Hi

I need to increase the value max_allowed_packet
In my /etc/my.cnf file i had
[mysqld]
......
set-variable = max_allowed_packet=16M

I changed the value to 20M & restarted mysql daemon
but the variable is still ste to previous value

there are no other my.cnf files, especially that I succeeded changing
another variable
this line occurs only once in my.cnf ( others are commented with # )

What other parameter could affect the inablility to change that ?
On the other server I can change that easily, but it's running msql 4.0


--
Regards

Greg
ladowny at w p p l
the address in the header is fake