Why do different pages keep jumping to the top? (see details please)?

I've been having this problem for several days on several different pages.

I'm using Chrome, but I've also tried Firefox to see if it helped (it didn't).

This is what's happening:

Liking comments or posts on Facebook, the page jumps back to the top.

Unable to comment or give thumbs-up or down on Yahoo articles; it jumps back to the top of the page when I try, unless I open another page with just the post itself.

Unable to "see more" on longer replies on both Facebook and Yahoo (the page jumps back to the top when I try).

I don't have a virus. I haven't been hacked. Javascript is working. I have very few extensions installed (Social Fixer for Facebook and that's it, other than Javascript and Flashplayer). And this is a new computer (had it a little over two months now). I've tried a Google search but haven't been able to find anything. I've also tried restarting my computer, no change.

Would someone help, please? How do I fix this?