Comment # 7 on bug 1078713 from Josef Reidinger

Roeland - do you remove that diagnostic partition yourself? is it still there
e.g. when looking from windows?

Sebastion - are you aware about any such change that can make parted to stop
seeing this diagnostic partition?

In general problem is that bootloader have that /dev/sda4 as extended partition
that is used for booting, but it is now /dev/sda3 which is something that
cannot be survived without using UUID or LABEL for remembering this partition.