Trackpad scroll function not working in any app - tried everything

Hello.

This is my 1st time writing in the forums, and although I have read multiple threads on this issue, nothing has yet solved my problem, including: http://support.apple.com/kb/TS1248, & http://support.apple.com/kb/TS1449. SO ANY HELP IS WELCOME! I have a mid-2010 MBP 13" intel-based dual core with Mavericks OSX 10.9.1 installed already a couple of months now. As of last night, my two-finger scroll does not function in any app. It is the ONLY function on my trackpad that does not work. I have tried changing all scroll preferences, restarting the browser (firefox 27.0.1) & computer, as well as opening Preview app 7.0 to see if it affects other apps as well. It does not work even in Finder. I looked in the permissions section of my apps by right-clicking on "get info" & there seems to be a discrepancy between the default users and their permissions. I am wondering if this is perhaps the problem and can be reset somehow to default settings or if there is a terminal command that can reset the trackpad (like the PC function in the device manager of the control panel, diagnose/repair)? I have a screen shot of the different users/permissions that I can send/post you if necessary, but you'll have to explain me how to do this, as this is my 1st post. Thank-you!