Go to Taiwan and find them!
I don't think I am desperate to watch Taiwanese movies. But don't you think it is bizzare, we can easily find Taiwanese books and CD's in Hong Kong. So it cannot be politics that stop Taiwanese movies coming to Hong Kong.
There are Taiwan films can be found in HK but actually the no. of films produced in Taiwan is really little and they are not all popular as Japanes and Korean films now. Recently "刺青" is an OK one! Of course《一一》is one of the best of 楊德昌 films.
Yes, 《一一》is one of his best films but I even like his earlier ones more. You could still find it at Central HMV.