Horizontal scrolling + ColVis issue

I've a table with content loaded via ajax with show-columns plugin.
live demo: http://tinyurl.com/bwbceb2

the headers cells are not aligned and if u try to show/hide columns or change their order the content overflows the table..
how can i solve this problem?

here is the snippet code about the table inizialitation:

$('#t1').dataTable({
"sAjaxSource": "array.txt",
"bDeferRender": true,
"sDom": 'C<"clear">lfrtip',
"sScrollX": "100%",
"sScrollXInner": "110%",
"bScrollCollapse": true});

maybe, by sDom, i can envelop the processing inside a div with overflow property setted up by css..could it work?

I mentioned this issue in another post, i'm sorry if this could be unfair but i really need urgent help!