I said a bit too quickly that the problem was hardware, because jaunty alpha/beta/rc had problems both with EXT3 and EXT4.
As I saw several people having the same problems as me, I reinstalled Intrepid (ext3), and I have no problem at all !
I think there was a regression between jaunty alpha 4 and jaunty alpha 6 (in kernel), everything worked fine about 2 weeks using jaunty alpha 6 EXT4, but after an upgrade, I have all the problems I described, which have persisted even after format/reinstallation.
If you need more information, please ask, I think it's a very critical bug if it is confirmed.
I said a bit too quickly that the problem was hardware, because jaunty alpha/beta/rc had problems both with EXT3 and EXT4.
As I saw several people having the same problems as me, I reinstalled Intrepid (ext3), and I have no problem at all !
I think there was a regression between jaunty alpha 4 and jaunty alpha 6 (in kernel), everything worked fine about 2 weeks using jaunty alpha 6 EXT4, but after an upgrade, I have all the problems I described, which have persisted even after format/ reinstallation.
If you need more information, please ask, I think it's a very critical bug if it is confirmed.