I'm using Cinnamon (on 12.10) on a laptop (Compaq 6710b business model) with an external monitor. Both screens run at 1680 x 1050, the external monitor is located on the right.
During normal operation everything works fine; windows open in whatever monitor my mouse pointer is when they open and I can freely drag them to the other monitor.
When I close the lid of my laptop both displays shut down as expected. When I open the lid, however, the lock window opens on the external monitor and any windows that were open on the laptop screen have moved to the external monitor as well.
Nothing happens between closing the lid and opening it; no suspend, powerdown, hibernate or anything, monitor stays attached; even mouse is untouched (pointer on laptop screen).
Is there any way to fix it so my windows stay on whatever monitor I left them before closing the lid? Alternative solutions are welcome.
Addendum; if the laptop suspends while the lid is closed and it's brought up again, the windows do stay correct. This problem seems to happen when the lid is opened while still running instead of when closing the lid.