[flexcoders] mx:TileList : Why drag doesn't works if allowMultipleSelection is activate

[isa_loyer]

I work with TileList to display image like a gallery. At start, I activate only 
drag option.

<mx:TileList xmlns:fx="http://ns.adobe.com/mxml/2009";
         xmlns:s="library://ns.adobe.com/flex/spark"
         xmlns:mx="library://ns.adobe.com/flex/mx"
         columnWidth="120"
         rowHeight="150"
         paddingLeft="2"
         paddingRight="2"
         paddingTop="2"
         paddingBottom="2"
         itemRenderer="fr.ui.display._43Imagerie.TileUnit2"
         doubleClickEnabled="true"
         dragEnabled="true"
         dropEnabled="true"
         dragMoveEnabled="true"
         verticalScrollPolicy="on"
         >
Now I try to add multiple selection possibility.

If this option is true (allowMultipleSelection), drag stop to work, do you know 
why?

Thanks for helping.