Comment 4 for bug 99908

Hmm, I wonder. Before starting the installer, could you please try editing /lib/partman/commit.d/30parted, and putting 'update-dev' right after close_dialog? So the whole script should read:

#!/bin/sh

. /lib/partman/definitions.sh

disable_swap
for dev in $DEVICES/*; do
    [ -d "$dev" ] || continue
    cd $dev
    open_dialog COMMIT
    close_dialog
    update-dev
done

I'd be interested to know if this helps; it seems like a good possibility, as the reason that mkfs.ext3 failed was that the device node /dev/sda1 didn't exist.