yeah i am a light armour wearer and I have that helm of V that gives you an increase on prices, it is labeled heavy and I started getting heavy armour bonuses, it freaked me out I was like, "what they heck, what piece of armour is heavy." cuz I had never been wearing any heavy armour. It lokks neat with my Ancient shrouded, too. But anywho it does not effect my light armour bonuses, so I would assume the same for your heavy armour issue, too.