Theme tab not dispaly for my new theme

I am using tabs module to shown my form in a theme tabs format , it is working fine in garland,but it is not display the tab in purchased theme , tabs are in the correct places but it is invisible , when cursor move on that we can see the tabs

help me to solve the problem

i am using the following code

$form = array();

  $form['example1'] = array(
    '#type' => 'tabset',
  );


  $form['example1']['tab1'] = array(
    '#type' => 'tabpage',
    '#title' => t('One'),
    '#content' => t('<iframe src ="/info.php" width ="700" style="border:0px solid #000000"  height="750" ></iframe> '),
  );
  $form['example1']['tab2'] = array(
    '#type' => 'tabpage',
    '#title' => t('Two'),
    '#content' => t('<iframe src ="?q=node/3" border ="0" width ="700" height="750" ></iframe>'),
  );
  $form['example1']['tab3'] = array(
   '#type' => 'tabpage',
    '#title' => t('Three'),
    '#content' => t('<iframe height="600" width="600" style="border:0" src="/Gic/a.php"> </iframe>'),
  );

  return tabs_render($form);