Hi,
Just to let you know I have an E555 as my personal laptop and have had this problem.
My cursor starts uncontrollably jumping around the screen if I sit a notepad or something on top of the laptop then remove it. It does this every time, even done it with a light letter, and the only way to fix it is to restart.
I don't think it is a hardware issue as I am currently using Linux Mint and cannot replicate the problem, seems to be a Windows or driver issues.