The bar is caused by how sense handles apps that are not in compliance with Google design standards for the menu button. The only way to get rid of it is to root your phone. HTC on some phones has dual purposed the recent apps button to also serve as the menu button, but not on the dna.
Sent from my HTC6435LVW using Android Central Forums
NOVA and APEX Launchers seem to do the trick for everyone else.
You can check the "Post your home screens!" thread for examples. No need to root for this.