Hello, I've upgraded a second server from Etch to Lenny as the first one with 2.6.25 etch-backports to 2.6.26 lenny. It was the same result. By chance initrd for 2.6.26 and 2.6.25 were rebuilt but not the 2.6.18 one then I can use this one to recover. After of course, it was the same solution. Cheers.