Logitech mouse previously scrolled through inventory one spot per mouse scroll wheel click. Now with 1.4.2 it takes a good spin, probably 10 or so clicks to scroll one inventory item, up or down.
Environment
Windows 7; Java ver 7 upd 4 32 bit.
Comments 2
Please see http://www.minecraftforum.net/forum/155-support/ for support issues.
This is specific to your hardware, not Minecraft itself.