Floater height max 2012

in max 2010 you could register a roller floater like this:

dialog = newRolloutFloater "WindowName" 170 -1

by setting the height to -1 the roller would take all max's height when docked.

In max 2012 it doesn't work anymore, the floater is like 1px high

is there a way to make it work in max 2012?