Can't get YUI Menu to display/interact correctly

Hello, I had the older version of YUI Menu to work--I don't remember the number, but I'm guessing it was 1.4; anyway, I tried to install the replacement 2 modules: YUI and YUI Menu and update the installation, etc. For some reason the menu won't show up properly, when I have the with markup option selected, the menu shows up completely expanded, when I have the javascript version of the top nav menu set, it only shows the first level of menu options, but doesn't expand at all--and the list of menu items is stacked vertically, rather than horizontally. Any ideas? Could it be having trouble accessing the YUI library? The default link to the library did not work, I downloaded the library and put it in files/library/yui but that path didn't work either? Any ideas would be greatly appreciated. thanks.