I've a problem with the msDropDown plugin, It seems to work perfectly but when I click the first time on it, the child box with the options appears only by 3px. Then with a second click, it works fine.
I'm using Chrome, Jquery 1.9.1 and msDropDown 3.5.2
Setting the line height in the css did not work for me, but with a bit of tinkering around, I found that setting the rowHeight property in the jquery.dd.js file did fix this problem.
e.g.
It's a bit bodgy as it means you need to know in advance how tall you want your items to be, and presumably it could cause problems if you have several msdropdowns on a page which you want to give different heights.
It solved the problem for now, though.