There is a very easy way to determine if your digital sensor needs cleaning. You may quickly determine if there is dust on your camera sensor. Point your camera towards a bright blue sky without clouds. Take a picture. If you see these fuzzy out of focus black dots in the sky then you have dust on your senor. At that point you should take your camera to a repair person to have the dust cleaned off of the sensor. The down and dirty way to test for dust. No blue sky ? then go somewhere where they have better weather like Maui.