Default sort order on the other table columns I render a table with theme_table() and use tablesorting (sql) for that. It all works fine. 

Except for the intial/default sort on the other tables. No user sort option defined yet. Example:

Name | Age ▼


Sort by "age" is defined in the $header. User clicks on "Name". That now gets sorted ascending. Regardless! I need descending.

Click:

Name ▲ | Age


But I need/want:

Click:

Name ▼ | Age


Studying the code that determines the default sort order, in tablesort_header, I come across the following:

else {
  // If the user clicks a different header, we want to sort ascending initially.
  $ts['sort'] = 'asc';
  $image = '';
}


I see no way to avoid this. Do you? Did I miss some parameter, option? I refuse to believe that Drupal makes such a silly assumption without letting developers override it.
No, it isn't possible at this point.

There is an issue for that, I suggest you try that out and report back so that it can be commited soon: http://drupal.org/node/109493