Genie effect freezing

Since installing Leopard, whenever I double click a window causing it to 'sail' (genie effect) into the dock, if I move the cursor over to dock to bring it out while the window is collapsing into it, that window "freezes" on my screen. It happens every time I bring the dock out while the window is headed (genie effect) into it.

This never happened in Tiger, so I am assuming it must be a bug in Leopard. Has anyone else had this problem?