Empty Tabs when not using equal sizing

Panes seem to have some dirty "helper panes" so tha if you use no style there will be blank / empty tabs.
Perhaps this is even a side effect of another module?

To correct that problem edit line 50 of tabs.inc:

if (!empty($pane_content) && !in_array($pane_id, array('empty_placeholder', 'add_button'))) {

(Make sure that the pane id is not such a "fake" value.
Alternatively an integer check might be a solution.

Could you please fix this in the next version?