padding/collision question

[Kieren MacMillan]

Hello all,

Shouldn't (or at least didn't at one time) dynamics and markup "fall" towards 
the staff if there is no collision?
[I don't keep old versions of the app, but I *swear* this is a recent change…]

For example, consider the snippet

\version "2.15.1"
\relative d''' {
  r2 r4 d^\ppp   |
  \override DynamicText #'X-offset = #-6
  r2 r4 d^\ppp
}

I would expect (hope!) that the second dynamic would fall towards the staff -- 
at the very least, I should be able to easily turn off whatever is keeping it 
aloft.
Any hints/answers would be appreciated.

Thanks,
Kieren.