Your tablet isn't supported in 11.04. Both the kernel wacom module and the x11 input driver are missing references to the model of wacom you've shown. If the kernel module ws working for this device you'd see somrthing like this:
[420349.922] (II) config/udev: Adding input device Wacom Intuos3 4x6 (/dev/input/mouse2)
[420349.922] (II) No input driver/identifier specified (ignoring)
[420349.923] (II) config/udev: Adding input device Wacom Intuos3 4x6 (/dev/input/event9)
[420349.923] (**) Wacom Intuos3 4x6: Applying InputClass "evdev tablet catchall"
[420349.923] (**) Wacom Intuos3 4x6: Applying InputClass "Wacom class"
[420349.923] (**) Wacom Intuos3 4x6: always reports core events
[420349.923] (**) Option "Device" "/dev/input/event9"
In your /var/log/Xorg.0.log file as you plug and unplug the device. Please do add anything from this log into your question just to make sure.
To get your device working, you will either have to upgrade to 11.10 or create (or ask for one to be made) a wacom-dkms package and updated companion xf86-input-wacom package which I created for 10.10 and 10.04 for wacom tablets that started working in 11.04. (if all that makes sense)