One of the compounding issues is that you have what looks like a tab in your menu, but isn't.  Here's the revised code:

$(document).ready(function() {
    var acc1activetab=$('#acc1 > li:has(a[href*="'+GetCurrentPageName()+'."])').prevAll().length;
    var acc2activetab=$('#acc2 > li:has(a[href*="'+GetCurrentPageName()+'."])').prevAll().length;
    if (acc1activetab==1) acc1activetab=-1; //If second (inactive) tab, none are active
    if (acc1activetab>1) acc1activetab-=1; // If more than second (inactive) tab, subtract a tab number
    
    $("#acc2").accordion({
        alwaysOpen: false,
        autoheight: false,
        header: 'a.acc2',
        clearStyle: true,
        active: acc2activetab
    });
   
    $("#acc1").accordion({
        alwaysOpen: false,
        autoheight: false,
        header: 'a.acc1',
        clearStyle: true,
        active: acc1activetab
    });
});


function GetCurrentPageName() {
    //return 'Link1'; //hard coded for testing
    var sPath = window.location.pathname;
    var sPage = sPath.substring(sPath.lastIndexOf('/') + 1);
    var index = sPage.indexOf('.');
    sPage = sPage.substring(0, index);
    return sPage.toLowerCase();
}

And a link to jsfiddle http://jsfiddle.net/zbRFt/

Better code:

$(document).ready(function() {
//    var acc1activetab=$('#acc1 > li:has(a[href*="'+GetCurrentPageName()+'."])').prevAll().length;
//    var acc2activetab=$('#acc2 > li:has(a[href*="'+GetCurrentPageName()+'."])').prevAll().length;
//    if (acc1activetab==1) acc1activetab=-1; //If second (inactive) tab, none are active
//    if (acc1activetab>1) acc1activetab-=1; // If more than second (inactive) tab, subtract a tab number
    
    $("#acc2").accordion({
        alwaysOpen: false,
        autoheight: false,
        header: 'a.acc2',
        clearStyle: true,
        active: '#acc2 > li:has(a[href*="'+GetCurrentPageName()+'."]) > a'
    });
    
    $("#acc1").accordion({
        alwaysOpen: false,
        autoheight: false,
        header: 'a.acc1',
        clearStyle: true,
        active: '#acc1 > li:has(a[href*="'+GetCurrentPageName()+'."]) > a'
    });
});


function GetCurrentPageName() {
    //return 'Link7'; //hard coded for testing
    var sPath = window.location.pathname;
    var sPage = sPath.substring(sPath.lastIndexOf('/') + 1);
    var index = sPage.indexOf('.');
    sPage = sPage.substring(0, index);
    return sPage.toLowerCase();
}

And better jsfiddle: http://jsfiddle.net/zbRFt/1/