Yes, so this is how you stream to your dreambox easily.
Open the dreambox's webserver in your browser http://dreambox
Click on ZAP
Click on Stream (oops, maybe this button needs a plugin, I didn't think about the fact that I have currently not the original image running)
Click on Settings
Put your PC's IP on the serverIP field
Activate "transcode Video" and "transcode Audio" if you stream something else than mpeg (e.g. an AVI)
Click on Change
Click on browse and select your file you want to stream
Click on "File" button, your local VLC client witll start and send the video to the dreambox.
Wait...
Wait a little more (up to 2 minutes)
The dreambox will show now the stream. Enjoy
Georges