Same problem here with Xorg 7.3 solved by the patch in ebuild p3 .
Did anybody report this to the linuxwacom bug trucker ? If so, I will fill a bug report soon.
BTW, why not using the RESTRICT="mirror" option in the ebuild?
--- linuxwacom-0.7.8_p3.old.ebuild 2007-09-24 17:06:29.000000000 +0200 ...