Points
1) you are missing a closing li tag after the first closing ul tag. Try adding that and see if it helps.
2) This:
ul li a:hover .long
will not work. ul.long is not contained inside the a tags, so it is not a child of the a tag. But that CSS is describing it as a child of the a tags.
3) Which IE - IE6? If so, your problem lies there - :hover only works on a(nchor) elements in IE6. Which may be where your problem lies. This:
ul li:hover .long
will work in firefox, because you can add :hover to elements other than a(nchor) tags. But IE6 will just ignore it.