I honestly don't know. I can't stand mozilla's sluggish interface for long enough to try either (that and it's uninstalled). It works fine in IE, though.
for the record, my logitech scrollwheel works fine on kmeleon, BUT - unlike in IE, it doesn't work until the current page has been clicked on... while it's highly unlikely that anyone would fail to figure that out, it couldn't hurt to mention it.
I checked on that bug where the scroll doesn't respond until you click. It's a known bug but no time frame when that will be fixed. It's specific to K-Meleon.