I have been examining your page and it seems that there may be an issue with the background for the area with the menu in it. Looking at the css it seems that you have this set to be white:
jpblack.css (line 261)
#outerWrapper #contentWrapper #nav {
background-color:#FFFFFF;
As for the scroll bars appearing this is due to the fixed positioning you are using on the div that the navigation is contained in. It looks like you may need to adjust this or remove it entirely.