I'm currently having a problem with the 3D view -while working on a model, I suddenly wasn't able to rotate my camera anymore. I can manipulate the model just fine, the camera is the problem. I checked the Manipulate Center Points, Lock camera and pretty much everything I could find -I even reinstalled Blender! Still stuck, regretably. My mouse works fine, it zooms in and out perfectly. I just can't seem to rotate around the mesh. Any ideas what could be the issue?
In the 3D view header, find the icon that lets you change your pivot point. Just to the right of that icon you will see an icon with three dots along the top and a left and right pointing double arrow below. Clicking on that icon toggles rotation. It's easy to click on it by accident.
I don't have enough reputation to comment, but have you tried pressing Numpad . (period) it sometimes can reset the view (best way I can explain it) or Shift+C if that doesn't work.