Comment 6 for bug 187909

Sorry for my inprecision, I'll try to explain it better:

When I right to a window's title a menu will appear.
In the middle section of the menu, there is a possible 6 elements:
  - Always on Top
  - Alway on Vibible Workspace
  * Only on This Workspace (this one is selected by default)
  - Move to Workspace Left
  - Move to Workspace Right
  - Move to Another Workspace -> a submenu contains the available workspaces

To trigger the bug, do these steps:
  1. Right click on the window's title and select the Always on Visible Workspace menu item
    Now the middle section of the menu will consist only these 4 items:
    - Always on Top
    * Alway on Vibible Workspace (this one is selected)
    - Only on This Workspace
    - Move to Another Workspace -> a submenu contains the available workspaces

    [Note that, the "Move to Workspace Left" and the "Move to Workspace Right" menu items have been disappeared, but the generic version "Move to Another Workspace" didn't.]

  2. Move the window to another workspace by right clicking the menu title, and selecting the "Move to Another Workspace" submenu, and here select an other workspace. (For example: Right Click -> Move to Another Workspace -> Workspace 2)

Now you have triggered the bug: the window is in a state where it is always on an unvisible workspace. You can see it's preview on Workspace Chooser panel-element (usually at the bottom right corner), but if you change Workspace the window will change Workspace as well (to an other one). It is even possible, to move the window to an unexistent (ie: 0. or 5.) workspace too. In this case you can't see its preview on any of the workspace's preview.

In general what the window does is: it keeps the distance between the visible workspace. Thus if you move it from the visible workspace by 2. It will keep this distance when you change the workspace, for example:

Visible Workspace Window
1. 3.
2. 4.
3. 5. (possibly not exists)

Other example: Your are on the 2. workspace, at you have moved the window to the first workspace:
Visible Workspace Window
2. 1.
1. 0. (not exists)
3. 2.

In the previous Screenshot1 you can see the unreachable window's outline on the Right Workspace, and Screenshot2 shows, when you simply change to the Right Workspace (nothing else happened, just simple workspace changing) the window which's outline was previously whown certeinly disapperad from the Wrokspace Chooser panel-element and you can't see even the window on the screen.

The same error occurs on the installed version of the Ubuntu as well.

I hope, I explained it better now.