aclocal m4 file needs to be updated
aclocal issues the following warning :
/usr/share/aclocal/ao.m4:9: warning: underquoted definition of XIPH_PATH_AO run info '(automake)Extending aclocal' or see http://sources.redhat.com/automake/automake.html#Extending-aclocal
I think your ao.m4 file needs to be updated. IIRC, these are minor (backward-compatible) syntactic changes.