I was having the same problems... apparently another version has been released, but isn't what the yahoo toolbar site downloads. Go through Mozilla add-ons and update to version 2.5.9.20130411104515. Link--- https://addons.mozilla.org/en-US/firefox... Seems to work for me with Firefox 20.
Yahoo Toolbar is at this time not working on firefox 20.0, uninstall it, find a install for 19, then it will work. If you do this, also turn automatic updates off or it will just updated to 20 again giving you the problem. Once yahoo toolbar comes out with an update I will test out FF20.0.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.