I also found what was my issue.
I reinstalled the linux-image package for the 2-6-20.15 kernel and now it boots fine.
It seems that in the first installation the kernel vmzlinux boot image was corrupted.
In the Dell D600 laptop model I didn't need to use the "noapic" option when booting the kernel.
I also found what was my issue.
I reinstalled the linux-image package for the 2-6-20.15 kernel and now it boots fine.
It seems that in the first installation the kernel vmzlinux boot image was corrupted.
In the Dell D600 laptop model I didn't need to use the "noapic" option when booting the kernel.
It seems that this was not a bug in my case.