Can't update template T3_bs3_blank

Hi

When I start a new site with T3 I make a copy of T3_bs3_blank by going to Template Manager > Templates, click on T3_bs3_blank and the choose "Copy Template" giving it a name like "Layout".
Now I do my styling on this new template, but this results in that I can't update the template afterwards when T3 is out with an updated version of T3_bs3_blank.
I can update the framework, but not the template?

Any clues on this issue?

Thanks!
/Thomas