I agree with Jim Cootes, this is
Bulbophyllum thaiorum (now more properly known as
Cirrhopetalum thaiorum)... in species, there is a wide range of variability, both in color and form. Colors of a flower are not the ultimate criteria for differing species, but can fall into the Subspecific category...
Bulbophyllum (including all segregate genera), as I see, is well known to display a wide range of variability, especially the same species originating from different areas...
Very nice flower though, these are interesting!
-Pat