Modal Window Picker

I tried to set a column’s control type to "modal window picker" with the FlexGrid but the picker button doesn’t show up. I read that this was fixed awhile ago: http://our.componentone.com/groups/topic/studio-for-lightswitch-2012-v3-now-available-many-flexgrid-fixes/
But with the latest version (2.0.20132.42), it doesn’t work.

Thanks for your help
Guy