Bethesda are working on a fix but it "will not apply" to those already experiencing the glitch. You need to load a previous save in order to experience the DLC.
Oh dear. It's almost become an institution for Fallout downloadable content to feature bugs and glitches. Remember when Bethesda's own Xbox 360 release accidentally littered one DLC package with exclamation marks everywhere? Oh how we all chuckled.
They're hard at work on a fix in the next patch, said "...if you already have a save game where the bug is occurring, the fix will not apply and you’ll need to revert to an earlier save prior to ED-E leaving in order to play through Honest Hearts."'s Nick.
For those having trouble with their Steam purchase of Honest Hearts they advise you to fire off the option to 'Verify Integrity of Game Cache'. If that fails then wipe your ini files suggests Bethesda. Have you been having issues with Obsidian's Honest Hearts DLC?