Where did all my disk space go? The hidden folder .root/.local/share/Trash

I could not explain that my hard disk was so full considering the files I had on it. Trashcan was emptied ten times. Did all the cleaning I could think of (see post before this one) but still found it unexplainable where the space went to. The Gnome Disk manager didn't provide the right answer. I installed the program xdiskusage. First I ran it and discovered some ten gig in the root but access denied; so I could not find out what it was. So ran it in the terminal: sudo xdiskusage . Then I discovered that these 10 gig where in the folder root/.local/share/Trash. Went there in Nautilus as root and unhid the local folder with Ctrl+H.
Tried to delete the files but after a short disappearance the files were recovered.These were mostly large incremental backup files that I had decided I wanted on an external hard drive and had deleted. Made with sbackup.
Anyway looked in the forums and found this suggestion:

In Hardy, the location of the trash has changed to

Code:

~/.local/share/Trash/files

To empty the trash this command should do it:

Hardy Heron:
Code:

Code:

sudo rm -fr ~/.local/share/Trash/files/*

Tried this but it didn't work out as it should. The files were still there.
Elswhere I found this:

Since it is a directory, you cannot just
rm /root/.local/share/Trash/files

You need to rm -rf /root/.local/share/Trash/files

I tried and finally I had ten more gig at my disposal.
But this raises some questions... how is it possible that there are two Trash locations and that one is hardly accessible for the common user? And how should he discover there are two trash locations? This is very confusing and this matter should be adressed in some way or the other. As many people use Ubuntu as a dual boot and may haved limited space to run the OS.

Update:

Again there was a load of files (ten gig) in the /home partition in folder Trash-0 outside user pablo and second user test. Because evidently not linked to a single user, I couldn't remove them using Nautilus or Krusader as root.
Only way to solve this to type in terminal

sudo rm -rf /home/.Trash-0/files