On the poster, the DVD cover and the film the title in characters is:
龍虎少爺
In pinyin probably: long2 hu3 shao4 ye3

You got this title as alias, but it seems to be the real title, as you can see below.

Here you can also read the name of Qiu Jian Guo. I can't find it among the credits.

Sorry I do not understand what you say, what is the relation between "Treasure Hunters" and "This is Kung Fu" ? Their chinese titles are completely different

I don't understand either.
I don't know how I could make such a mistake.
Maybe I wanted to copy and paste and took the wrong title?
Sorry.