i notice that your most of your shots are properly exposed, but there is just too much noise in all of them. what iso did you use? ISO 100 is the maximum you can go for night shots with decent noise level for an A40. trying resizing your photos to a lower resolution too. If there is still a lot of noise, you could even smudge them away in photoshop.
Lower ISO supposed to have less noise, so theorectically using ISO 50 would be best for u.. But maybe u can try ISO 100 as well, as a shorter shutter speed with ISO 100 may give better results as well.. just a suggestion..