Scroll wheel support: Carbon vs. Cocoa

[Mikuro]

I've noticed that some of Apple's programs, like iTunes and the Finder, support mouse-wheel-controlled scrolling of inactive windows, whereas most programs will only let you scroll the active window, even if the mouse is hovering over an inactive one. I find this feature very useful in the Finder, and wish it were enabled in every application. Is there any way to do this?

Also, does the inconsistency in behavior stem from the fact that iTunes and the Finder are based on Carbon, whereas most other programs, like Safari and TextEdit, are Cocoa-based? Why should Carbon have better scroll wheel support than Cocoa? Usually it's the other way around with these things.

By the way, I'm currently using USB Overdrive to drive my mouse.