Flex 2 sdk (not sure if 3 does this too):

Why does VBox appear to retain a verticalGap (extra spacing pixels) between
mxml components that have 'includeInLayout" set to false? It seems to
successfully factor out the size of the component, but not the automatic gap
padding that the container itself adds. Is this a known bug?

Eh, nobody's seen this? Surely putting in gap pixels for components that
aren't even drawn isn't the desired behavior? I guess it's a bug... isn't
anyone doing dynamic changing ui stuff? (add/remove fields from forms at
runtime) That can't be the case..