boot splash screen

[Luca Ferrari]

Hi all,
I've got a strange behaviour of my laptop at boot time (kubuntu 7.04 - Ati 
Radeon Mobility X1600: it does not shows any line or splash screen while 
booting. I've tried also installing the ubuntu splash screen packages but it 
does not works. My grub file contains the following definition:

title           Ubuntu, kernel 2.6.20-16-generic
root            (hd0,4)
kernel          /vmlinuz-2.6.20-16-generic 
root=UUID=9368a1e6-858f-4283-a81d-c506efe2281b ro quiet splash
initrd          /initrd.img-2.6.20-16-generic
#quiet
savedefault

Anyone can tell me how to configure grub to show a splash screen and, in the 
case, what is doing during the system boot?

Thanks,
Luca