[jQuery] Problem jQuery UI tabs effect

Hi,
I mounted a tabbed section on jQuery UI 1.2.7. I use ajax to call a
file .html each time you click a tab.
Everything works correctly until you add an effect. To be more
concise, everything continues to function well even after adding the
effect, but now every time you press a tab or tabs, the browser goes
to the top of the page.

JQuery function to which this happens is:
$(function() {
  $("#tabs").tabs({fx: {opacity: 'toggle', duration: 'fast'}});
  });
A demonstration of how the error: http://ico.comxa.com/tabs/ui_tabs1.html#tabs


If the function is simply the following, the problem disappears:
$(function() {
  $("#tabs").tabs();
  });
Hi,
I mounted a tabbed section on jQuery UI 1.2.7. I use ajax to call a
file .html each time you click a tab.
Everything works correctly until you add an effect. To be more
concise, everything continues to function well even after adding the
effect, but now every time you press a tab or tabs, the browser goes
to the top of the page.

JQuery function to which this happens is:

 $(function() {
  $("#tabs").tabs({fx: {opacity: 'toggle', duration: 'fast'}});
  });

A demonstration of how the error:http://ico.comxa.com/tabs/
ui_tabs1.html#tabs


If the function is simply the following, the problem disappears:

$(function() {
  $("#tabs").tabs();
  });

... and here the demo to work correctly, but without the effects
applied: http://ico.comxa.com/tabs/ui_tabs2.html#tabs

Anyone knows how to solve this error?
Thank you very much.