See if this helps:
Regarding the issue of trying to leave partitions unmounted:
In gParted right after you finalize your actual partitions, you go to the next step to decide which partition is mounted at which mount point and check off which should be re-formatted (make sure you have a file system on the partitions at this point, otherwise you'll get an error). Here's the trick: In order to get Mint to ignore a partition, you have to delete the proposed mount point and blank out the partition entry. (It's annoying because I have so many partitions.)
hda has 3 partitions:
hda1 / for my main Debian OS
We now know this is not the recommended setup.
hdb has 10 partitions:
hdb1 / for another Debian
hdb2 swap for Debian
hdb5 / for openSUSE 10.2
hdb6 / for Ubuntu 6.10
hdb7 / for Linux Mint Bea
hdb8 swap for 5, 6, 7, 9, 10
hdb9 / for Linux Mint Bianca
hdb10 currently empty
hdc has 1 partition:
hdc1 /woc 160GB of Wide Open Country
So when I installed Bianca, I had to delete lots of suggested mount points.
I distilled my list to just this:
All of the remaining entries were deleted so Bianca would ignore them and wouldn't tell me I had unmounted partitions.
This topic leads right into a suggestion about newbie mounting schemes: How easy is it for an installer to accept a SINGLE partition rather than a single hard drive as the chosen install location, and then the installer re-partitions this single partition into scorp123's recommended scheme of /boot, /, /usr, [/opt,] [/srv,] /var, /home. Newbies don't necessarily want to know about how linux should be organized when they're just getting started, but they also may not have an entire hard drive to devote to linux.