I have spent 3 days trying to solve this problem across nearly a dozen Macs....problem is NOT your hardware, problem is a bug in Mavericks. After being told by tech support to do everything from resetting SMC to resetting NVRAM to forcing Spotlight to re-index, to turning "always" on in scrolling setting in settings as suggested here, trashing plist as suggested here, it turns out that nobody at Apple has responded to the THOUSANDS of posts relating to this problem yet is completely aware of the problem. The problem is a Mavericks glitch and they are well aware of the problem.
Here's a snippet from recent support chat...even the support tech is having the same issue.
"I am so sorry this is happening and do fully understand as my Finder is doing the same thing. I am hoping an update will be released soon that resolves this issue as I know first hand how annoying it can be!!"
Would be so nice if collectively tens of thousands of hours didn't have to be wasted by thousands of people experiencing a problem, trying to figure out a solution when their issue could be simply solved by a single post from Apple letting everyone know that they were aware of a particular issue and working on a fix. Communication with Apple is all too often 1-direction, users submit things but nowhere are users told by Apple "got it, we're aware of and working on this particular issue". Think of all the support expense, user frustration and wasted time this would save everyone!
I want my 3 days back.