1. Set the window list to group similar windows
2. Open nautilus for your home directory
3. Open another nautilus window by e.g. opening a subdir in your home dir
4. Open the trash. (Now you will see that the window list icon changes to trash)
5. select the window opened in step 2 or 3
6. Close the trash window
7. The icon in the window list keeps on being the trash icon

I would expect that it would change to one of the icons of either the home dir
or the subdir.

NOTE If you close one of the other icons the trash icon dissapears.
NOTE It also happens if you i.s.o. trash use one of the other icons which has a
custom icon such as computer or burn:///

Maybe this bug should be solved in the gnome-panel. The window list group icon
then should always show the icon of the last selected window in that group