You'd better re-register to the POEA office or enquire them about your situation. Someone told me that aliens can use Chinese residence permit to return China. However, I don't think residence permit is equal to Chinese visa, maybe someone pass the custom with the Chinese residence permit, but I read a news that a german woman holding the Chinese residence permit is refused to enter China at Pudong airport. You should apply for a new work visa to China.

Mr.Alan,thanks for your reply..Yes, I guess I really need to re-register to the POEA as Balik Manggagawa, to avoid problem.

But, I don't need to get another Chinese visa because mine is still valid until Oct.2010..If you're holding a Chinese Z visa means you can enter China and work there,but your employer will go to the local PSB before 30 days upon entry, to have you registered,so your Z visa will be cancelled and changed to Chinese residence permit and it is valid for travel in and out of the country within its validity period.