Ok… found a solution that works for me, but doesn’t use the abbreviations in locale.php… So it really only works for (as above) links like “01.2007”.
In general-template.php I simply changed line 343
$text = sprintf(__(‘%1$s %2$d’), $wp_locale->get_month($arcresult->month), $arcresult->year);
to:
$text = sprintf(__(‘%02s.%d’), $arcresult->month, $arcresult->year);
…For me this topic is resolved. Further advice always welcome. ;o)