I found an extremely interesting and carefully documented timeline on the history of sex abuse in the Church – it comes from a website called "Priests of Darkness - Sex, Sin and Satanism in the Catholic Church". It looks very sensationalist, but in fact the articles are well-written and seem to be carefully researched.
A couple of highlights from the timeline:
* April 30, 2001 – The CDF secretly issues Sacramentorum sanctitatis tutela, or Safeguarding the Sanctity of the Sacraments (link) under Pope John Paul II's name. This replaces Crimen sollicitationis with a policy even more secret and ruthless than before. All priestly sex crimes are to be placed under the CDF, which usually will authorize the bishops to conduct trials themselves. However, clerical homosexuality is not even mentioned.
* May 18, 2001 – Ratzinger quietly adds the cover letter (pdf) for the new policy, making cases "subject to the pontifical secret." In other words, absolute secrecy is imposed on all who know about them under pain of automatic excommunication that only the pope can forgive.
Those two items explain a lot, but the whole document is fascinating, and charts a course going way back to the 15th century.
http://archives.weirdload.com/timeline.html