Hoverinfo display error when i use ggplot2 with Plotly

I follow the example given in the website ,but i got a different hover label (the left), the hover data label should look like the right hand side
My R version is 3.3.1 and ggplott2 is 2.1.0.


dsamp <- diamonds[sample(nrow(diamonds), 1000), ]
qplot(carat, price, data=dsamp, colour=clarity)

Any help would be greatly appreciated.