Notification Area has Problems with notifications on dual screens

Binary package hint: gnome-panel

The notifications are not working correctly with dual screen configurations.

Two examples:

When Rhythmbox is running, its not accessible over the notification area icon and notifications are now shown.

When new mails or IM messages arive, the notification icon for evolution, empathy oder gwibber is not showing it.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: gnome-panel 1:2.30.2-0ubuntu0.2
ProcVersionSignature: Ubuntu 2.6.32-24.39-generic-pae 2.6.32.15+drm33.5
Uname: Linux 2.6.32-24-generic-pae i686
NonfreeKernelModules: nvidia
Architecture: i386
Date: Wed Aug 18 19:58:41 2010
ExecutablePath: /usr/lib/gnome-panel/notification-area-applet
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
ProcEnviron:
 LANG=de_DE.utf8
 LANGUAGE=en
 PATH=(custom, user)
 SHELL=/bin/bash
SourcePackage: gnome-panel
XsessionErrors:
 (polkit-gnome-authentication-agent-1:1719): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
 (gnome-terminal:23081): Gtk-CRITICAL **: gtk_accel_map_unlock_path: assertion `entry != NULL && entry->lock_count > 0' failed