Open accordion on category click

Open skin/frontend/base/default/tm/navigationpro/js/navpro.js

and find the following lines (~332-335):

Event.observe(accordion, this.options.onEvent, this.activate.bind(this, accordion), false);
if (this.options.onEvent == 'click') {
    accordion.onclick = function() {return false;};
}

Add the following code after them:

var a = accordion.previous();
Event.observe(a, this.options.onEvent, this.activate.bind(this, accordion), false);
if (this.options.onEvent == 'click') {
    a.onclick = function() {return false;};
}

Save the file and clear browser cache.