Nikon d5100 sigma 10-22 mm lens not taking photos?

It just won't take. The camera screen doesn't come up with any errors or anything, it just won't take any pictures. It's very frustrating as this is a lens I only just got, and I really want to take some photos with it. :/
Any help?

Added (1). Never mind, i figured it out. It will only work when looking through the lens, and not in the live view mode. :/ Kinda annoying, but oh well. :3

Dslr cameras aren't designed to be used with the screen anyway… You should always be using the view finder.

Using live view is the surest way to take bad photos, camera shake and all. The only acceptable way to use live view is with a tripod.

That flip out screen just enforces bad habits.

I really find it annoying that they put LiveView in dSLR cameras. Now I have to pay for something that I never will use ever at all.