With my logitech revolution, scrolling in MC is utter pants!!
It has a freewheeling mouse wheel (no clicks) which is great, but in MC, scrolling down is much the same as you. Nothing happens until I give the wheel a real good spin, which causes the list to shoot straight to the bottom.
At which point, I can scroll upwards as slowly as I like and the list responds nicely to the wheel.
I mentioned this some time ago and was unceremoniously shot down in flames for it.
When using MC, I've actually adapted to this behaviour by shooting to the bottom of the list without thinking about it, then scrolling slowly back up to find what I'm looking for.
I've experimented with mouse settings to the point where I'm sick of the sight of mouse settings.
I don't see this problem in any other program I use.
I don't know what the answer is.
-marko.