I just installed 11.10 and found that once I minimize the terminal window, I can't bring it back. All other Windows are getting minimized to the Unity launcher and I can relaunch them from there. If I go to the launcher and click on terminal a new terminal session is created and the old one is lost completely. This is the first time I am facing such a problem and all my previous installations of 11. 10 didn't throw up any such behaviors. Any suggestions?
Reset the Unity:
Press Alt+F2 and run the following command:
see this answer too:
This is a relatively benign & graceful solution.
I had a similar problem which occurs when Terminal is unlocked from launcher
The open windows are frequently not associated with the Terminal launcher even though it was used to start them.
Another clumsy and inelegant method that I have used, reloads X-windows and hence Unity, by typing Alt+Print Screen+K to kill and restart X-windows.