If the Key Editor is placed into a separate monitor and then closed, when reopening it, the Key Editor appears in the main monitor and does not retain its original position.
1.) Open Key Editor
2.) Place Key Editor window in separate monitor
3.) Close Key Editor
4.) Double-click any MIDI part to re-open Key Editor
5.) Key Editor opens in main monitor, not separate monitor
Not sure what to tell you…
I am using C8.0.10 on the same Mac OS X as you, and, here, the Key Editor window reopens in exactly the same place as where it had been previously (even when on my 2nd monitor screen).
Try (temporarily) removing your Cubase Preferences.
Thanks for your response. I removed the entire Cubase folder from ~/Library/Preferences/ and the problem still persists. Is there a setting you’ve selected to make this happen?
What’s interesting is since my other monitor is smaller, it remembers the size of the Key Editor window when I bring it back up but not the location.
No, (I can’t think of any setting that could cause this). Have you tested with windows other than the Key Editor (e.g. the Mixer window)?
Thanks for your help on this.
The problem doesn’t happen with any other windows (Score Editor, Instrument Windows, etc). However, if I reverse the monitor positions of the Project Window and the Key Editor, there’s no longer a problem because the Key Editor opens in the correct place.
My guess is there’s a bug concerning the Key Editor only opening up in the Main Window of the OS where the Menu Bar sits. If I switch the location of the menu bar to the other monitor in System Preferences, the Key Editor will only open in that monitor. Weird.
Thoughts?
Well, I know the reply “Well, it doesn’t happen here” is of no help, but… it really doesn’t happen here! 
I have the same issue did you find the cause?
Thanks
This nearly 10 year old topic isn’t relevant to current versions.
Hi,
If the Editor doesn’t follow the selection (Preferences settings) then is every single MIDI Part owning it’s own Key Editor. So the Key Editor of MIDI Part A can open at other place as the Key Editor of MIDI Part B.
But the Key Editor (of the given MIDI Part) should open at the same place, where did you close from.