Have you equipped any skills yet, or are you just using Heavy Strike so far? If you haven't equipped any skills, when you pull up the Action/Trait screen, it should show 0/x Action Points at the top--x standing for how many points are available. Actions like Concussive blow take 3 to equip, Light Strike takes 0. When you log on next, try using this macro:
/eaction 2 "Light Strike
/eaction 3 "Concussive Blow
That will equip those actions on your action bar in those slots (change the numbers as you will). As you gain higher ranks, more AP will become available to you. If that doesn't work, it sounds like your char might be bugged.
Edit: P.S. It's strange, but you don't need a parenthesis at the end of an item/action/etc.'s name, just at the start.
Edited, Oct 7th 2010 6:18pm by Klarus