DocumentViewer doesn't associate pdf files by default

[Giova84]

I have installed DocumentViewer using Haikudepot.
When i double click on any pdf files, to open them with DocumentViewer, an alert window tell me that "Could not find an application to open foo.pdf (application could not be found) etc.. etc.." Then offers me to find the proper application (clicking on "Find" button), but DocumentViewer doesn't appears inside this list. Obviously i can manually set the preferred application using the "FileTypes" preflet, but the process should be automatic.

I'm on Haiku hrev48053 gcc2h