It's a simple fix. Just add a 'rm -rf /etc/distcc' in targets/stage3/stage3-preclean-chroot.sh and targets/stage2/stage2-preclean-chroot.sh after the 'run_emerge -C sys-devel/distcc || exit 1' line.
Created attachment 77363 [details, diff] patch to cleanup /etc/distcc In case you were too lazy/busy to code it yourself ;)
I've fixed this in catalyst with a slightly different approach.
Fixed in 2.0_rc17...