I had only used my brand new Oster blender about a half a dozen time and it always worked fine. A couple of months went by without using it though and when I did the motor hummed and strained but the blades wouldn't turn. I took the blender off of the base, put a thick rag over the blades and rotated them by hand. At first they were very stubborn and hard to turn but I could feel them loosen up pretty quickly. Back on the base and they spin fine now. I guess maybe I'll turn the blender on every so often if I'm not using it as the blades seem to have a tendency to freeze up.