windows randomly move between desktops when connecting / disconnecting monitors

I use a laptop with an external monitor and would like to connect / disconnect monitor as I, say, go to the meeting.

I have several workspaces and organize the windows per task on one or several neighbouring workspaces.

As soon as I connect or disconnect an external monitor all that arrangment is gone, windows end up on random workspaces, often on top of each other, and it is not like there is some user friendly way to combat chaos in unity - you can either see all windows of a single workspace, or all workspaces at once, but not individual windows. So I have to arrange the windows again, then I need to quickly go show something to a collegue with my laptop but her place, and all the arrangement is gone.

Basically this makes me hesitate to attach a second monitor or move freely with my laptop.

Reproducing:

1. place several terminal windows per workspace and in each type "echo this terminal is on workspace 1x1", " ... 1x2", "2x1" etc, where the numbers are cartesian coordinates of the desktop.

2. maximize some of the terminals, keep others normal sized.

3. connect a second monitor.

4. go from window to window and see if you can discover the system by which they ended up where they ended up.

5. if some terminal is maximized on a secondary monitor, unmaximize it and watch it disappear into some random place.

6. drag the terminals to the desktops they were on originally (same monitor they were on: you haven't dragged them to the second monitor, so they shouldn't be there)

7. disconnect the monitor and repeat steps 4 - 6.

8. now repeat from step 3.

9. If you have several external monitors with different arrangement options remembered - go to the different monitor every time you start the reproducing cycle.

10. try to find existing bug related to the experience on launchpad.

How it must work

1. arrage the windows

2. connect the second monitor

3. the first time around the windows must stay where they were - same workspace, same monitor

4. drag some windows onto the new monitor

5. disconnect the second monitor

6. the windows are where they were after step (1)

7. connect the same monitor again

8. the windows are where they were after step (4)