Hi all, when I import my videos (vob) kdenlive import only the first 10 or 12 seconds... why?!?!?

It is some incompatibility with FFmpeg and MLT, but I have tested a few different VOBs in the past with MLT and Kdenlive but not run into this problem. Try this workaround to remux but not transcode:
$ ffmpeg -i your.vob -vcodec copy -acodec copy out.mpg

thanks for the workaround, because I had the same problem.

Could this be integrated into the import process in some way?

There is no "import process," per se. However, there is a Transcode function in the Project Tree where it can be integrated. You can do that today, and we can make it a built-in option in the next release.