Ah...you throw that at me like I've never heard of Pen-Ek Ratanaruang or seen (and admire) any of his films. Pen-Ek is a THAI filmmaker, and all of his films are considered THAI in their nationality (because they are made in Thailand).
'tis funny you cite the oft-erroneous IMDB in an attempt to shoe-horn a Thai film into the DB, as the film's official website notes it as a co-production between Thailand and the Netherlands...
http://www.invisiblewaves.com/
...on the "Credits" page.
Anyway, do whatever you like! I think with the inclusion of innumerable entries in the DB, from countries other than Hong Kong (and largely to suit people's own personal tastes and whims), that the DB has sufficiently started to slide into a complete loss of focus...and is no longer a project I can be completely enthusiastic about being participant in.
