skype icon isn't visible in panel

Binary package hint: gnome-panel

after switching to natty, I used unity for a few days, but I didn't like it - so I switched to gnome-classic.

I found that the skype icon isn't visible in the panel. this is quite annoying if I accidentally minimize skype because it's inavailable then. the interesting thing is, that this problem does not exist in unity.
I've never had this problem in maverick.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: gnome-panel 1:2.32.1-0ubuntu6.4
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
Architecture: amd64
Date: Tue May 3 08:23:36 2011
GConfNonDefault:
 /apps/panel/general/applet_id_list=[applet_2,clock_screen0,notification_area_screen0,trashapplet_screen0,fast_user_switch_screen0,applet_0,applet_3,applet_8,applet_1,applet_4,applet_5,applet_6,applet_7,applet_9,applet_11,applet_10]
 /apps/panel/general/object_id_list=[menu_bar_screen0,browser_launcher_screen0,object_6,object_8,object_9]
 /apps/panel/general/show_program_list=true
 /apps/panel/general/toplevel_id_list=[bottom_panel_screen0,top_panel_screen0]
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-panel
UpgradeStatus: Upgraded to natty on 2011-04-29 (3 days ago)