Why my pointer cursor jumps?

I have a Sony Vaio VPCEB1Z0E. The operating system is windows 7 and the processor is Core i5 with 4 GB RAM. Last 2 months i'm having a problem as the mouse cursor jumps drastically after half and hour of the laptop starts. It only happens when i use the pointer. I even disabled all multi gesture options and i don't have any animated theme for the cursor. I tried using a optical mouse and it works fine and never jumped. I bought the laptop last year and i think i still have the manufactures warranty. I also reinstalled the alps software from vaio software support and nothing changed. Using a optical mouse is very painful for me as im not used to it. I need an actual solution guys. No time wasters please. Hope among you there is someone who actually knows what to do. Thnx.