Alt+Print screen shortcut doesn't take screenshot of a window ($5)

Alt+Print screen take the screenshot of whole screen. It should take screenshot of a window. I tried to reset the keyboard shortcut but doesn't work. Screenshot application works randomly. Sometimes I am able to take screenshot of a window but sometimes not. I have attached the screenshot of keyboard shortcut page(crop by gimp).

ProblemType: Bug
DistroRelease: elementary OS 0.3
Package: elementary-desktop 1.363+407~ubuntu14.04.1 [origin: LP-PPA-elementary-os-daily]
ProcVersionSignature: Ubuntu 3.13.0-45.74-generic 3.13.11-ckt13
Uname: Linux 3.13.0-45-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CrashDB: elementary_meta
CurrentDesktop: Pantheon
Date: Thu Feb 26 10:51:48 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-02-11 (14 days ago)
InstallationMedia: elementary OS 0.3 "Freya" - Daily amd64 (20141209)
SourcePackage: elementary-meta
SuspiciousXErrors:

ThirdParty: True
UpgradeStatus: No upgrade log present (probably fresh install)