When I was playing through one of the levels on campaign today, I got to a part where you have to melee/chainsaw some boards, so you can pass into the next room. After I did this, I couldn't perform any type of melee attack at any time until a few chapters later, where I had to chainsaw more boards that were blocking a door.
This was quite annoying and made the gameplay a bit harder. If I was playing Insane, I probably wouldn't have been able to complete it. Anyways, just thought I'd report it.