I had rebuild debian kernel 2.6.32+28 with the patch http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.32.y.git;a=commit;h=787814b206766e5a6f21aa2aac0c6685b46821d3 and now, it's booting fine. can someone push it upstream ? (ubuntu kernel in my 2nd post is unrelated,maybe it's an ubuntu patch problem)