Comment 28 for bug 106209

Part of the reason why this problem hasn't been fixed is that it has been tagged incorrectly. It is not an e2fsprogs bug, but, as described above it is an Ubuntu installer issue. Unfortunately, I have not been able to find a way correctly tag this problem inside Launchpad as an installer issue, so the wrong people are paying attention to this bug.

To be fair to the installation people, this is somewhat of a hard problem, since different people use different partition schemes, and partitions that should be shared (such as /home) and partitions that shouldn't (like /var) aren't necessarily easily determinable by a program not possessing artificial intelligence. You can use heuristics, of course, but heuristics are often incorrect.