Debby, are you using a wide focal angle (less than 30)? Such values distort the perspective, resulting in a "fish eye" look. This is obviously very apparent on things that should be strait, like houses and walls. If you want to encompass a wide range in you picture, my advice is to use the usual architectural rendering trick: Use a "normal" lens angle (like 36), move your camera far enough to see everything you want. Now you'll probably have unwanted "empty" areas around. Just render a larger resolution than you need, and crop the unwanted parts in a paint program....