Hmm... I did the same thing, then rescanned after plugging back in and it confirmed the change. BTW mine is on OSX w/ 64 steps. I guess it doesn't affect the absolute lowest settings (in my case that maps more like 7% - 15%).
EDIT: Playing with it some more, my impression is perhaps step 1 may be considerably louder than it was stock but the gradations are producing smaller changes? I tried pushing it to my threshold of pain and it was maybe at 5 full bars on an older recordings with minimal compression applied. (20/64 steps). It's hard to say, but before I may have gotten away with up to more like 4 to get that volume level.
Edited by bobeau - 5/31/13 at 11:03am