My unstable doesn't boot anymore

[Cesare Leonardi <celeonar@tiscali.it>]

This morning i have updated my Debian Sid but that left my system in an 
unbootable state.
After loading various modules, with apparent no errors, the following 
messages followed (hand written, so excuse me if they are not 100% close 
to reality):

Begin: running /scripts/local-premount...
Attempting manual resume
Done.
mount: mounting /dev/hda2 on /root failed: no such device
Begin: running /scripts/log-bottom...
Done.
Done.
Begin: running /scripts/init-bottom...
mount: Mounting /root/dev on /dev/.static/dev failed: no such device or 
directory
Done.
mount: Mounting /sys on /root/sys failed: no such file or directory
mount: Mounting /proc on /root/proc failed: no such file or directory
Target filesystem doesn't have /sbin/init

Then a BusyBox shell open up.
If helps, i have seen the following modules inside /proc/modules:
ide_cd
cdrom
ide_disk
e100
mii
ohci1394
ehci_hcd
uhci_hcd
usbcore
piix
generic
ide_core
thermal
processor
fan

As you can see the modules to mount my ATA (not sata) drive are in 
place. I have tryed to mount root manually:
mount /dev/hda2 /
but it fails.

Here is some details of my system:
linux-image-2.6.16-1-686         2.6.16-5
udev                             0.089-1
initramfs-tools                  0.59b
grub                             0.97-7.1
klibc-utils                      1.3.3-1
The machine is a Sony Vaio VGN-B3XP notebook, a tipical Pentium-M with 
i855 chipset.

I haven't filed a bug since i can't understand what had caused the problem.
The update that today aptitude had proposed me was not too big (the 
previous was less that a week ago) and the packages to upgrade seemed to 
me not so critical: no new kernel, no initramfs-tools. I remember that 
there was an upgrade for grub and klibc. I can't remember if there was 
also a new udev, but looking from packages.qa.debian.org, it is possible.

After rebooting with a kernel 2.6.15 (that i keep for safety), i have 
tryed regenerating the initramfs:
dpkg-reconfigure -p low linux-image-2.6.16-1-686
But this haven't solved the problem at all.

I haven't seen bugreports or messages on the list about similar problem: 
either it is a problem specific of my system or this weekend many user 
has preferred to go the sea.   ;-)

Have someone any suggestion?

Regards.

Cesare.