Problem with wallpaper and weather/clock????

I have put some great wallpapers on my mem card but when I go to change the wallpaper to one of the ones I have put on the mem card it only allows me to choose a part of it I cant get it to fit to the screen like the ones that are already loaded, I have the right size 240x320 has anyone any idea why it won't fit? Also I cant get my weather to show on the clock htc widget that I choose, the digital clock is fine and if I touch the clock it will open the weather but will not show it on the home screen underneath the clock as it shows when you first choose the widget, I have set my home town and like I said wil lopen and show if I press the clock, any ideas as to what I am doing wrong????