if you mean your sidebox header text , then here is the code in CSS that you need to look for


.leftBoxHeading, .rightBoxHeading {stylesheet.css (line 313)
background-image:url(../images/sidebox_header_bg.gif);
background-repeat:no-repeat;
margin:0;
padding:0.5em 0;
text-align:center; // add this to align header text
}