In latest 11.10 Ubuntu there is a bug about system printscreen feature. When you click on it, it is generated black blank screen. I found kind alternative app for this feature. It is called Shutter.
Let’s install it. Open your terminal(by default it can be opened by alt+ctrl+T)
apt-get install shutter
Then let’s create shortkey for it.
1. Open System Settings->Keyboard->Shortcuts->Custom shortcuts. Click + button.
2. Then small window with 2 fields will appear. Type any name for Name: field, type shutter for command field. Click to enter.
3. Then in custom shortcut list you will see your given name to shutter. In right side there is New shortcut. Click on it then press to alt+prtscr on your keyboard. Then click to OK.
That’s all. For printing any screen just press alt+prtscr.