It fixes important bug found in 0.6.13 (http://www.exit1.org/dvdrip/dist/patches/transcode-0.6.13-bitstream.patch) plus several others. " 05 Nov 2004; Marc Hildebrand <zypher@gentoo.org> transcode-0.6.13-r1.ebuild: Added patch to fix dvd::rip issues. Patch and ebuild submitted by folken see bug #70092" -- this patch would not be nessesery if updated version of DVDRip would be used (0.51.2). It is however considered an unstable one.
Transcode-0.6.14 is in portage now.