Drupal 7 DHTML Menu 7.x-1.0-beta1 - Upper-Level Menu Items' Menu-Collapsed Icon Does Not Switch To Menu-Expanded When Clicked.

Updated 2013.12.17

Solution at drupal.org "DHTML Menu" Documentation page https://drupal.org/node/2126031.

Essentially...

I resolved this problem by switching
from 7.x-1.0-beta1 (2010-Nov-09)
to 7.x-1.x-dev (2011-Nov-09)

and you must
"Clear all caches"
every-time after you run the update script
[root]/update.php.