Mac OS X cannot be installed on Macintosh HD... (Easy Fix)

I just upgraded to Mac OS X 10.6 "Snow Leopard" yesterday and the installation didn't went smoothly, which is contrary to what I expected. An error message told me:

"Mac OS X cannot be installed on "Macintosh HD", because the disk cannot be used to start up your computer." It also displayed an image of a drive with a yellow triangle on it. So that means I was in trouble.

Actually, there's a long thread right now at different Mac forums where a lot of people are looking for a possible fix on this hitch. That's why I'm going to share how I solved my installation issue and successfully upgraded from Mac OS X Leopard to Snow Leopard.

I realized that the cause of this particular problem is the Linux partition alongside my Mac OS X. --I installed Linux (Xubuntu) using rEFIT. The simplest and safest solution that I tried (and luckily worked) is this:

1. Get a Linux Live-CD (preferably Ubuntu), pop it in, boot it up, and log in (don't install it).
2. Open a partition editor (preferably GParted).
3. Shrink the Linux partition that's immediately next to your OS X disk. You will need to free at least 128MB of disk space from your Linux partition.
4. Apply the changes and wait patiently. I waited for more than an hour for GParted to finish its task.
5. When completely done, restart and remove the Linux Live-CD.
6. Put in the Mac OS X 10.6 Snow Leopard installer and boot it up.
7. If you are lucky like me (hehe), the "Mac OS X cannot be installed on..." error should be gone by now and you can then proceed with your installation or upgrade.

I’m planning to write a quick review of Mac OS X Snow Leopard soon. So, to those of you who are interested, watch out for it.