Mine has just done the same thing. There is a rubber gasket at the base of the blender that will rot and go bad if liquid is left in there. The best way to avoid this for as long as possible is to rinse/clean the blender immediately after it's used and then turn it upside down to dry. Mine has been fine for a long time, but my kids use it and sometimes forget. I'm just going to have Blendtec replace the gasket, it will be as good as new!