Header doesn't resize after sScrollY setting

HSomb

Hello,

Setting up a DataTable I have this issue where, if I do not define a sScrollY, the table width resizes dinamically with the browser window. As soon as I set the the sScrollY I get the desired height but no dynamic width resizing anymore. More specifically, it resizes for bigger resolutions than the originally loaded one but not for smaller. Without sScrollY it resizes in any situation.
I've my width="100%" in the table tag and I'm using DataTables 1.10.12 and the situation reported happens in IE, Firefox and Chrome.

The code for initialization is the most basic one:
$('#mainDataTable').DataTable({
sScrollY: "200px"
});

Any insight would be greatly appreciated.

Thanks in advance!
Best
-H