Visa for leisure trip to Harbin

Hello

I am a Filipino living in Phnom Penh. I hold a Cambodian long-term visa (one year blue or E visa) valid until August 2013. I have been living here for two years. I am a pilot.
I would like to visit Harbin for 5 days. This will be a short trip as a tourist.
Can I apply for a single-entry tourist visa at the Chinese Embassy here in Phnom Penh? Or do I have to fly back the Philippines and apply in Manila?
I have these documents:
1. Copy of long-term lease contract for my apartment here in Phnom Penh
2. Passport (valid until June 2016)
3. Copy of my long term 1-year Cambodian visa (valid until Aug 2013)
4. Copy of my previous 1-year Cambodian visa (July 2011 - Aug 2011)

Please advise if there is any chance of a successful application based on the information I provided above. If it is unlikely that a visa will be granted, I will go to South Korea instead.

Thanks.
Ben