[tabletool] checkAll then uncheckall but i can't checkAll again

i know this action could be strange, but some user are stranger with computer ...

some topix are helpfull, so i have found how to un/check All checkbox into a datatable:

to check:
$('td input', oTable.fnGetNodes()).attr('checked', 'checked');
or
$('td input', oTable.fnGetFilteredNodes()).attr('checked', true);

touncheck:
$('td input', oTable.fnGetNodes()).attr('checked', '');
or
$('td input', oTable.fnGetFilteredNodes()).attr('checked', false);
or
$('td input', oTable.fnGetFilteredNodes()).removeAttr('checked');

but if user want check again all checkbox, all input have attribute "checked" with "checked" value, but all checkbox aren't checked at screen (i have try to go next page to refresh, but nothing change ...)

need help, thanks :)