I do not believe the issue involves the horizontal drop down menu.

A quick fix would be to edit your stylesheet.css and use a negative margin of about two or three pixels.

Change
stylesheet.css (line 677)

Code:
#navSupp {
background:transparent url(../images/footerT.gif) no-repeat scroll 0 0;
color:#869492;
padding:45px 10px 10px;
}
To
Code:
#navSupp {
background:transparent url(../images/footerT.gif) no-repeat scroll 0 0;
color:#869492;
padding:45px 10px 10px;
margin-top: -2px;
}