Stack icon won't refresh in SL

[hupple]

I put app and download folder in the stack.

After I finish downloading a file through firefox, its icon is still blank although I can see the correct icon in Finder.

And if I copy a new version app to the app folder to replace an older one, its icon in stack will be the icon when the replacement begin, not the correct one.

Is it a common problem?

 

[mattrgee]

I noticed this after installing Photoshop and adding it to the stack, fixed itself after a reboot.