My mom has been having this strange problem with her Logitech MX 1000 mouse to the left of her cursor are these sort of horizontal squiggly lines similar to a dollar sign although hard to describe... the mouse works fine but it's still pretty irritating. She says sometimes it gets in her way when typing in an address.

I'm going to her house tomorrow to check it out but since I've never encountered anything like this before I have no idea what's going on. Any ideas?