Question regarding stacks in Leopard

Hello. I've recently upgraded to Leopard and so far I'm enjoying the experience. Stacks are a nice feature but there is something I am somewhat curious about. I currently have my applications folder on my dock, which when clicked on expands into a grid. I've noticed that Third Party Apps, like Firefox (my default we browser), do not show their icons when displayed in a stack grid. If you open up the folder in finder, the icons display normally. Is there a way to have the proper icons display when using stacks like this?

Thanks.

You were right. A simple restart fixed that issue. Thanks for the help.