Comment 18 for bug 29894

a workaround might be that "PrtSc key" always opens the screenshot tool MAIN interface.

that way users can set the delay and various other options.

http://imagecdn.maketecheasier.com/2008/11/gnome-screenshot.jpg
http://www.myapitips.com/wp-content/uploads/2011/03/Screenshot-2.png