Anyone else seen this?
Ya I have to set it manually. Never really worried about it, but as a side note I frequently use Desktop X either with or instead of OD, so maybe it is related. Might be interesting to learn if it works as expected for people who don't use DTX.
It doesn't particularly bother me, just wanted to let you know that it's not just you.
Added trivia: As I play with this it looks like "Automatic distance" sets the bottom of the icons against the edge of screen, not the bottom of the dock against the edge of the screen. May be useful trivia. Again though, no biggie to me.