Are 'ye using a laptop? If so, what kind? (Mac or PC?)
Sometimes (on PC laptops, anyway), the F# controls have different settings prebuilt into them, which would make them not work on FH unless you hold down the "fn" button on your keyboard as you press your function key of choice to get the camera to work.
On laptops they do that sometimes because of limited space on keyboards, so they have to put different functions into the Function keys rather than leaving them plain like a full Desktop would have.
If that makes any sense at all. I'm just really bad at explaining things apparently x'D