hello i am from south africa intending to visit a friend in china 28th may to 2nd june.

my passpost expires october 17th 2011 but my alien registration card has validity until january 2014. i was advised by the travel agent that my passport should have at least 6 months validity beyond my stay in china but has read on the embassy website that if longterm residents in japan has alien registration cards that have working visa with validity over 6 months this is ok. just wondering if it is absolutely necessary to renew my passport before my trip in this situation....difficult as it takes quite a long time to get the new passport and a temporary one is only issued for emergency travel. any advice on this would be greatly appreciated. thank you.