After installing Xorg 6.8.1, I found out that very few of the above steps were necessary to use the Graphire2! My current kernel (2.6.5-7.111) already has a wacom module. `tail -f /var/log/messages' shows that the kernel module `picks up' insertion of the Wacom's USB cable into the USB port. `wacdump /dev/input/event3' showed that my Graphire2 was successfully sending messages (to the wacdump program anyway).
Modifying /etc/X11/XF86Config was more traumatic, however. SaX2 needed to be re-built (see 6.7.3). However, SaX2 wrote a faulty XF86Config! I needed to go to the ServerLayout section and manually add lines for the stylus and eraser (see 6.4), which are named `Mouse[5]' and `Mouse[7]'. Those manual changes will be over-written by SaX2 when SaX2 is used again...
Only the `stylus' end of the Wacom can be used as a pointing device (usually). GIMP 2.2, however, can recognize both the stylus and eraser independently. From the menu choose `Preferences', then `Input Devices --> Configure Extended Input Devices'. Change Mouse[3], Mouse[5] and Mouse[7] to `Screen' mode (otherwise they will just be treated like a normal mouse). A writer on the linuxwacom.sourceforge site reports that the `Window' mode is more subject to bugs i.e. crashes. If, when using the `blunt' end of the Wacom pen device, you change the GIMP to eraser mode, then GIMP will `remember' that the `blunt' end is the eraser. However, you are not limited to using the blunt end as an eraser. It can be used as the spray-can tool instead, for example.
Using `xidump Mouse[5]' showed that the Wacom driver was detecting when Button-1, the stylus, goes `down' but not when it goes `up'. This caused a lot of trouble when using applications like the GIMP. The problem was in the XF86Config. I had to change...
Driver "mouse"
Identifier "Mouse[1]"
Option "Device" "/dev/input/mice"
Option "InputFashion" "Mouse"
Option "Name" "PS/2-Mouse;IMPS/2"
Option "Protocol" "imps/2"
Option "ZAxisMapping" "4 5"
EndSection