Thanks!
I so downloaded 3MX with 2.6 kernel
Booted from an ubuntu live CD
create 2 partitions using gParted (16M fat16 + 974M ext2)
open terminal and move to root privileg (sudo -i)
untar file to SD2
copy boot/uImage to SD1
insert the SD into my LLL
fn+leftshift, power, F2 ..... and nothing

still this PINEAPPLE white screen...
tried again with F2 at power, F2 quicker...nothing more
it seems I'll need the serial interface to understand what's bugging
I read on a post 1Go NAND flash LLL could be different from 2Go NAND flash LLL
I have a 2Go version, if it matter...