Updating jQuery breaks collapsible fieldsets on admin pages

I recently enabled several jQuery related modules on my setup: jQuery Update UI, Tabs. Upon this, I was unable to make use of collapsible fieldsets on admin pages.

Template.php includes this piece of code:

// We need jQuery included on all admin pages.
if (arg(0) == 'admin') {
drupal_add_js('misc/jquery.js');
}

Deleting this solved my problem.
Perhaps this above isn't necessary in a Drupal 6 template anyway?

Wanted to share with others who are using this theme...