How can I print-screen just one window and not my entire desktop?

I'm not sure if Ubuntu 12 has a similar settings tools. Pull up System Settings and look at your Keyboard settings. Shortcuts contain many keys that your system may be expect you to use. Make sure you don't have a conflict with another keyboard shortcut and check that your screenshot shortcut is what you are expecting to use. I've disabled the general ALT key for dashboard that might interfere.

This is what it looks like in Ubuntu 13:

I don't have a fix for this issue, but I could suggest another option: use Shutter . It's a pretty advanced screenshot application that lets you do a lot more than just take screenshots - including choosing where to save them.

My 'answer' to this, at least for now was to look for the app itself. So I went to dash home (top left icon with circle) and looked for the 'Screenshot' app then when I saw it I dragged it to my unity icons on the left and now it's simply available as an app and I get the options of capturing just the window, etc. when I use it.