We have had the plastic attachment that the blade is attached to break 2 times now from trying to blend up a simple smoothie, and break once trying to blend up a cup of almonds with 3 cups of water.  The thing starts smoking and then locks up and the plastic parts crumble into bits.  We are finally through with this blender.  We ended up paying over half of what we bought the thing for in replacement parts and now that the third blade assembly has crumbled we are done.  We have a Cuisinart coffe maker, coffee grinder, ice cream maker, food processor and waffle maker and have never had problems with any other Cuisinart products, but they obviously have not perfected their blenders for heavy duty usage.