FWIW, it is:
pentax.gs@pri.pentax.co.jp
Via: http://forum.xitek.com/thread-1194052-1-1-1.html (in Simplified Chinese)
The case is about what happened back to May. It seems that the customer service was really good for that particular case and the supporting staff who handled the case was really helpful. But I just wonder if the above email address still works as it does contain the "pentax" name in it, which should have already been killed by Ricoh since August 1st! Damn, Ricoh! >:-(