Nikon 24-70mm not taking sharp photos?

I bought my Nikon 24-70mm brand new but photos came out not sharp and most of the are out-focused. When I switched back to my Nikon 60mm prime, photos come out crystal sharp. I heard 24-70mm only accept faster shutter speed 1/250 or above, is that true? And what other settings I need to be aware of?

Anyone is loving your 24-70mm and manage to take sharp photos? Would you like to share?

I'm very depressed because I spent so much money and don't want to return it since it's hassle.

Your sincere and professional advices are deeply appreciated!

Btw my camera is Nikon D90.

So, if you own the 24-70mm, why not confirm with your own camera that it will work fine at all shutter speeds? Hmm…

It's one of Nikon's high quality full frame camera lenses so it should be pin sharp.

Are you sure you're not accidentally knocking the focus ring and taking it out of focus?

Whoever said it's only good for fast shutter speeds is an idiot. You can use any lens at any shutter speed, you just may need a tripod.

Mine is very sharp, even wide open.

Are you sure the photograph is in focus? Are you sure you are not seeing motion blurriness?

You can use that lens in any shutter speed your camera can support. Where did you hear 1/250 nonsense?

You are holding one of the best zoom lens Nikon has produced. It is a pro level lens, as you can tell by the gold ring. If something is wrong with it, you should either return it or send it for repair.

By the way… If you are going to use it with your D90 and have no plan to upgrade to full frame sometime soon, then you'll end up with kind of an odd zoom range for general use. You are aware of that, correct?