This is a horrible way to file a bug report and I'm aware of that, but this needs to be considered.
Throughout various upgrade and/or update procedures in Ubuntu and it's variants the user gets a display asking where to install grub(2). There is a suggestion that if in doubt to install to the mbr of all drives.
Unfortunately most new (and some old) users have no idea how drives/partitions are designated in Ubuntu, and they're clueless as to what an mbr is!
So basically you see a screen that says, "if in doubt select all", and you do so. Now, I'm aware those are not the exact words but I've been following (and trying to help folks fix) these problems since Lucid was released.
It's particularly troublesome when someone installs grub2 to an NTFS partition with a Win OS so I'd at least suggest making grub installation to an NTFS (or any FAT) partition very difficult.
Honestly I'm not sure what the solution should be, but I know Colin Watson deals with a lot of these grub2 issues and I've come to trust his judgment. Consider the following options:
#1: Display nothing but drives, that is "sda", "sdb", etc, and NO individual partitions. But create another "advanced" tab/option to allow installation to a partition.
#2: Increase the amount of text explaining the difference between drives and partitions, why it's a bad idea to install to a partition etc. IMHO that's a horrible option. (The more text the less likely a new user is to read it.)
#3: Figure out a way to always have grub(2) install itself where it was to begin with. (maybe a bad idea if the original install was wrong.)
While I think option #1 is great I have no idea how complicated that would be.
Does any of that make sense?
I'd be glad to test any potential "fixes" :^)