i managed to solve the problem after debugging my jquery code
i had to modify the selector and make it more specific
the updated function would be :
function stretchTabs() {
var tabNums = $('#consultancyTabs:first-child ul:first li').length;
var w = 1000 / tabNums;
var wi = w - 10 + "px";
$('.ui-tabs .ui-tabs-nav li').css({
'width': wi
});
$('.ui-tabs .ui-tabs-nav li a').css({
'width': 90 + "%",
'text-align':'center'
});
}
Cheers :)