One problem related to engine belts and pulleys has been reported for the 2005 Porsche Boxster. The most recently reported issues are listed below.
Vehicle was 2005 Porsche Boxster. Car engine self-destructed while driving highway at 70 mph. Cause was failure of intermediary shaft bearing at 29,000 miles as determined by engine dissembly. Car had been properly maintained and serviced by Porsche facilities for its life. Intermediary shaft failed after bearing failed, sending metal pieces throughout engine including into oil sump. Timing belt perforated camshaft cover. Engine was irreparable. There are many other reports on internet sites, easily searchable, for "Porsche engine failure" of this type.