Why does Google Maps sometimes return English address when it should return a Chinese address

This is my search api call:

http://ditu.google.cn/maps/geo?q=39.544387,115.799217&output=xml&sensor=true_or_false&key=abcdefg

and it returns a Chinese a开发者_开发问答ddress,

but sometimes I find it returns an English address stored in my mysql database,

so what's wrong with it?

Thanks

Usually Google returns funny things when it cannot locate the address. Did you check the return code?

Have you set the language property?

http://code.google.com/apis/maps/documentation/javascript/reference.html#GeocoderRequest