Header alignment with bootstrap (collapsed container)

zwoop

I'm using bootstrap and I've got an accordion where the tables are hidden by default and when the table is shown the header is misaligned.

"$($.fn.dataTable.tables(true)).DataTable().columns.adjust();" doesn't seem to do anything but maybe I'm calling the function at the wrong place.

I inserted an alert, to show if it is called at all.

Can anybody give me a hint, what I'm doring wrong?

Here's the example: http://www.veridian.de/collapse-test.html