This issue is similar, but not identical to https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/215750
When the 8.04 installer's Manual partitioning option is chosen, the partitioner code looks at the user's hard drive and then displays the list of currently existing partitions.
See the attached screen snapshot for an example.
The problem with this display is that an important piece of information is not as clear as it should be: which partitions will be used *and* which partitions will *not* be used. To find out for certain if a partition is *not* going to be used, the user has to first select the partition from the list and then click the "Edit Partition" button in order to bring up an additional dialog. Not very user friendly.
Or, the user has to sort of infer from the "Type" column that if a partition does *not* have a value listed for "Type" then the operating system will not end up using that partition after the installation. That's not very precise. Further, it appears that in at least one case, this approach is not always accurate. If the "Type" of a partition is shown as "swap" the user can edit the partition and specify that the partition should not be used (and in fact, no entry will end up in /etc/fstab), but it will still be shown in this list with a "Type" of "swap."
Seems like the solution would be to add another "Type" value to this display: "Not Used." That way, the information from the pop-up dialog for "Edit Partition" would be available in this dialog.
Bad things can happen when the user interface is not clear: https:/