I can confirm that bug. Happens also in edgy with an encrypted ext3 partition.
a workaround is to renice the kjournald process i.e. renice -p `pgrep kjournald` -- Write load on DM-Crypt LUKS partition with reiserfs jams system https://launchpad.net/bugs/82528 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
