Dimage Z1 night shooting

Hello. everytime i try to take some night shots with my Z1 i get
fustrated. imagine a big city view by the ocean. i can't use the flash
so i set the camera on the tripod and the problems start. no focus, i
always get the red dot meaning no focus, with night program selected
or not. if i go manual and set the camera to self timer i never get a
really clear night picture. the lights always seem to be blurred and
so are the buildings.no zoom used also. i increased sharpness but
still no better results. what drives me mad is the no focus thing...
any sugestion?
i can send samples of what i am talking about.

thanks
Gus