I'm running the 1.42 patch, and my deathknight has about 3 in critical hit, and it works. Every once in a while the words critical hit pop up, and the screen shakes (love the effect btw) so I'm guessing it works for me.
Other info... I'm in act1, and my DK has a 2 handed sword...
By the way, don't forget that there is a difference between a "one handed" skill, and a "one handed with shield" skill!! If you're carrying a shield, you'll have to learn the appropriate skill.