20GB HDD is only letting me use 6GB

I'm at a loss here. My 20GB HDD that I've had since launch has decided that it's only going to allow me to use a very small portion of it. I realize that a 20GB HDD is only good for around 13GB due to formatting and system files. I'm ok with that, but there has to be something else taking up a boatload of space. Here's a breakdown of my folders:

Games - 5.5 GB

Gamer Profiles - 13MB

Themes - 82MB

Gamer Pictures - 6MB

Avatar Items - 84kb

System Items 696kb

That's only a grand total of 5.6GB of data. It's telling me that I only have 166MB of free space left. So, what's using up the rest of the space and how do I free that up?

Also, when I hit X for "Delete Suggestions" the first one that pops up is "Chime", which it says is an Xbox LIVE Arcade Game, but is not listed anywhere else... not in my games folder, not in my profile, not in my game library.... there must be some other BS that's stuck somewhere too.

game updates most likely. They take up space and i dont think you can see them when you go to memory management. If you perform maintenance on your HDD you might find that missing space will return but of course your updates will be missing.

Figured this out. Chime was a game that didn't finish downloading, so I deleted that to free up about 800MB. The big one though was Final Fantasy XI. Apparently, deleting it from the HDD doesn't free up all of the space it used. I had to put the disk in and uninstall from the viewer, which freed up a whopping 8GB!

If you have music on your drive it won't show how much space it takes up. Maybe that could bethe problem if you don't have music I don't know what else it can be.