Thanks again! This worked even better!
Following I try to show you the development:
Before t3 update last week the sub menus looked like that:
The tab sat pretty tight on the green line, the footer looked like that.
After t3 update the view changed to this:
The tabs changed their size into the whole width of the grid, the footer remained the same as before.
This the site looked like after adding the code you posted first:
This was the view after adding your second code snippet
Looks pretty much like it should be. :-)
The only difference is the fact that their behaviour towards the thin green line changes, the gap grows from tab to tab:
It's also visible on the other sub menus, build with the same "nav tab" option:
http://mm-moerz.de/index.php?option=com_content&view=article&id=65&Itemid=176
Though I'm a bit bemused. "Nav tab" is standard Bootstrap/t3 option. I guess many other people use it, is it just me having this change in behaviour?