Probably one of the worst areas on the codex is Titles, maybe Species. The titles seem to have suffered a major change after Beta, and apparently the codex was too UN-important to update it. I barely pay attention to them because you mostly will get them upon completion of a quest/series of quest, or they just don't exists. I expect in a future cleanup of the codex they will just be deleted.
BTW, I sent a request to customer service and I got my Jedi Weapons codex from Tython which apparently was bugged and now isn't.
So keep sending those requests. I have had 3 codex fixed in the last couple of weeks on my toons (assigned to me after proving I should have earned it).