In a lot of situations you will be touching down below the bugged speed. This is normal. However, you shouldn't be touching down below Vref +5. You also shouldn't be flying an approach above the bugged speed or touching down above Vref + the gust additive.
- have to disagree there, oak - you should aim to be at Vref(+) at 50' but bleed off to something like Vref-5 at touchdown.