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

Question

I could swear I've always been able to do alt-printscreen to get 'just that window' but right now I am getting my entire desktop.

Any idea why this would be or what I can do to get my ability to do small window screen shots?

I've tried a lot of combination with the ctrl, alt, shift and print-screen keys but no luck, nothing happens in response. One option: shift-ctrl print-screen lets me do a selection using a cross hair to size out the screen capture but I don't know where this gets saved. I'm not being given the choice and it's not in Desktop or Pictures.

I use an external keyboard, but I've tried using the laptop's own keyboard and no difference.

I am running Ubuntu 12.04 and the laptop is a Samsung Ultrabook 900

Update: I rebooted and it "fixed" it - for now. However this is not the first time I've seen this so I'm still curious as to why it happens, what I can do to fix w/o reboot and if other share the same problem.

Answer 1

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.

Answer 2

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. Here's the link to it.