Hello Vitor,

Thanks for replying.

The only ajax refresh that is performed on the container which holds the list is when the it´s clicked on the chevron-up or down to expand the table. 

Are you handling the OnChange event of the checkboxes in any way?

Do you have any element on your page that could be submitting your page?

I can´t believe I figure out how to fix.

Before calling the javascript function ChangeTab() I call the function:

osAjaxBackend.BindBeforeSubmit(function(){             document.getElementById('"+checkboxSelected.Id+"').checked = true; 

});

Doing that it worked for me. The thing is, I don't know exactly what was causing it, but doing this, helped.