A friend mentioned this bug to me before and I once noticed it too on an alt. The only time I could ever reproduce it was when I deleted the saved vars for a character and it would go away the next time I logged in. And its actually a GloryLib bug and not a bug with HonorFu, but GloryLib is full of bugs and other issues right now anyway.
I've seen this before, but never had a chance to track it down completely. It *seems* to be a bug in doing next-day rollover stuff when you haven't been PvPing for multiple days... e.g. if you last PvP'd 3 days ago, the first time you earn honor it tries to roll your previous honor out of the 'current' list, but forgets to mark it as done, so rolls it again every time you earn honor.
Not sure exactly what's going on, but that's more or less the behavior. Reloading your UI after you earn some honor will "fix" it, though I'd love to see an actual real fix in place.