HotkeyNet doesn't do anything with the scroll wheel -- doesn't look at it, doesn't simulate it. The only way I can imagine that HotkeyNet could affect the scroll wheel is that HotkeyNet's mouse hook might slow it down very slightly. But HotkeyNet installs a mouse hook only if you've defined at least one hotkey with a mouse button in its trigger. If you don't do that, there's no mouse hook.