i made a dirty hack in category-template.php to make the standard category links look something like this:
/a1/a2/ becomes
/a2/
/a1/a2/a3/ becomes
/b3/
etc.
code:
// quick hack. just don’t return the parents
// return $chain;
return ”;
(the category name itself is removed by entering /. in the permalink options, category-base)
now i don’t have to bother with removing the disfunct links in the template.
Isn’t someone able to fix the nested categories thing when there is no category base tag?