Hi,
Sorry if this has been mentioned.. I searched but couldn't turn up anything relevant but may have missed it.
I've just updated (as it came bundled with the Adium update). Since then the icon you see when the growl notification displays is the growl one. Previously it displayed the application icon (eg mail) or the persons IM avatar.
Also to note is that there doesn't seem to be any interaction between Adium and Growl since updating.
Thanks for any pointers,
Adam