I have a new Wacom Graphire 2 (usb) that I just got working.  The three
wacom devices are using Absolute coordinates in XF86Config-4 (because the
howtos all recommend that setting).

If I set all three devices (stylus, eraser and mouse) to Screen mode, then
stylus and eraser work (mouse has some problems, maybe contending with the
PS2 mouse, but I'll track those down some other time).  But since my screen
is big and my window may not fill it, I end up having to draw in a tiny
postage-stamp area.  I'd prefer to use Window mode and have the full area
of my tablet correspond to the image window (that is what it's for, right?)

If I set any of the three devices to Window mode, and set the stylus
drawing tool to the ink pen, then as soon as I touch stylus to tablet, gimp
crashes, in ink_pen_ellipse, line 786 of ink.c (the line where it's calling
ink_options->function()).  It turns out that x_center is nan, though
y_center looks more reasonable.

We got here via ink_button_press, and it looks like that nan X coordinate
came from 
  gdisplay_untransform_coords_f (gdisp, bevent->x, bevent->y,
				 &x, &y, TRUE);

I haven't traced it any further than that yet -- had trouble debugging
because of the server grab (I have to debug from another machine and my
laptop batteries ran out.)  Looks like maybe I can just comment out the
grabs in ink_button_press if I want to debug this more easily.  Let me know
if you need more details or further tracing.

I also checked 1.3.7, but it looks like 1.3 doesn't handle tablets yet?  It
has Device Status but doesn't see anything but core pointer, and it doesn't
have the Input Devices dialog.  Or has that just moved somewhere else?