Here's an Airworthiness Directive (AD) which shows issues with this rudder and hydraulics system:
http://www.airweb.faa.gov/Regulatory...6?OpenDocument
As for many companies using the A310/A300 - good for them! I guess they'll wait until a serious accident occurs and then sadly pretend to the press that they made a mistake keeping such old aircraft in service instead of upgrading to, say an A320 series.
John