The question has been raised why Diodon is not running anymore after updating from  Maverick to Natty. If you have encountered the same problem I hope the following explanation will clear it up.

So in Maverick Diodon is linked against several libraries such as libdbusmenu-glib.so.1. This library has been updated in Natty and is there available as libdbusmenu-glib.so.3. This is actually not a problem as there are different debian packages available for Maverick and Natty which link to the different libraries.

However a problem can be raised when updating from Maverick to Natty. During the update process Ubuntu disables all 3rd party apt installation sources including the Diodon ppa. So the system will get updated but the correct Diodon version for Natty won’t be installed. This means the old Diodon Maverick binary, which is linked against libdbusmenu-glib.so.1, is still on the system. As this library is not available on Natty, however, it can not be started anymore.

To get around this, the Natty Diodon ppa needs to be configured and the Natty Diodon version installed. This can be done with the following commands:
sudo add-apt-repository ppa:diodon-team/stable
sudo apt-get update
sudo apt-get install diodon

So this way Diodon should be up and running again.