Problems with DVR 8204S: can't see the video stream

[jumpjack]

I am able to correctly see my DVR from remote PC, but I have an additional difficulty: I can't see the video stream! I can see any page "published" by the DVR, but the video page just show 4 black squares.
I can properly see videos only from my local network, so I guess it's a matter of port redirection.
Unfortunately, no clues about ports used for streaming are provided in the manual!
I guess used port are 64000, 64004, 64008 and 64012, because I "downloaded" from the DVR a javascript file which uses the internal activex to show the stream. But, although I redirected the ports on my router, I'm still not able to see the video strams!

I think my DVR is a Vtech, as I can barely see such an advertisement on the page where I bought it from:

http://www.kingshopitalia.com/dvr-videoregistratore-4ch-lan-web-mjpeg-500gb-p-138.html

But no clues about the brand are available in documentation or on the DVR, just marked as "8204S".

I also received QQEye, a SW for Symbian phones, but even it is not able to view the video! How can i figure out what the cellphone SW is sending to my video server upon attempting getting the video?

Does it exist any free generic-DVR viewer SW?