libtidy-ruby had a similar issue: segfault caused by internal API changes in latest libtidy-0.99.0 (in particular, TidyBuffer struct was changed since 20051018-1, see #462325).
It is quite possible that PHP bindings for libtidy need a similar update to bring it up to date with Tidy CVS. -- Dmitry Borodaenko -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]