This is bad for Mazda, but at least they tried fixing it by replacing the engines...though with little success.
Link to the Japanese page for recalls on RX-8 can be found below (just google it to translate it into english):
Year 2004:
http://www.mazda.co.jp/recall/20040226.html
Year 2005:
http://www.mazda.co.jp/recall/20050721B.html