VOSTRO 1500 INTEGRATED WEBCAM DOESN'T WORK

I have bought a new notebook Dell Vostro 1500 in december. At the start the webcam worked (in really I haven't used it many times). Today I tried to make a photo with Dell webcam center and the led of the webcam became "on" but after the 3 second of waiting, the programme sent a message that said it wasn't possible to catch photos and Try to link again the webcam and restart the operation. Also with the others fucntions of the programme the webcam doesn't work.

N.B. the webcam become "on" and Vista recognises it. I have tried to reinstall the driver and all the programmes of the webcam but the problem is still present.

There's anyone that can help me?? 

Thanks