ltablex.sty missing from libtheora-1.0beta3
Beta2 included a file doc/spec/ltablex.sty. Beta3 omits this file. The result of which is that the documentation build fails on latex installs that omit the ltablex.sty file as a standard part. RedHat Enterprise Linux 5 is one such distro.
I believe there is some reticence about the licence that the ltablex.sty file is released under which prevents it being included in some Latex builds.
The file needs to be included back into the directory that uses it or the build fails.