It seems I have been having a problem in Win 8, both CP and now RP where I will be typing along when suddenly the cursor jumps to another location and all of a sudden my sentence cont's in the wrong spot. Creates a little excitement in reading a thread. I played around with different browsers (IE, Chrome and FF) and the problem was common to all browsers. In trying to troubleshoot this problem I found that my touchpad S/W was not installed in Win 8 RP. When I checked the Control Panel, Mouse properties, I was missing several options in the Touchpad properties.
I went to the Sony web site and downloaded and installed the Alps Touchpad app. Now when I open the Mouse properties window I see some additional options that seems to have stopped this jumping around. I have to believe I'm not the only one with this problem. Try it and see if this helps.