I experience the same problem with oneiric alpha 2.
I listened to the notify messages that xfce4-notifyd receives using dbus-monitor. It seems the problem is network-manager. Take a look at the captured notification method call (attached). It seems nm-applet explicitly requests that many "Don't show again" action buttons, so IMHO it's not xfce4-notifyd's fault.
I experience the same problem with oneiric alpha 2.
I listened to the notify messages that xfce4-notifyd receives using dbus-monitor. It seems the problem is network-manager. Take a look at the captured notification method call (attached). It seems nm-applet explicitly requests that many "Don't show again" action buttons, so IMHO it's not xfce4-notifyd's fault.
Please confirm.