Hello,
To fix this open up your color1.css (line 793) file (or perhaps color2, color3, depending on what you are using)
Change the below margin-top from 4 to 3:
#navv ul li a.active {
background:transparent url(../images/color1/menu_left.gif) no-repeat scroll left center;
color:#000000;
margin-top:-4px;