Lost scroll in listbox

I have a “track list” that looks like :

class TrackList : public ListBox, public ListBoxModel {

which works perfectly well on windows
but not on MAC (OSX Leopard 10.5.3) : the scroll bar can’t be moved using the mouse
I can just click in the listbox and use the keyboard but clicking on the scrollbar’s little arrow does not work either
(using JUCE 1.45)
it goes through Scrollbar::mouseWheelMove() but does not scroll

Thanks for your help

There’s nothing wrong with listboxes on the mac, I use them all the time. Are they working for you in the juce demo?

my mistake : I forgot a lost call to updateContent()