DVB Dream freezes

[gecko]

Hallo,
I'm new to this stuff, so please be patient.
I've searched both the forum and the web, but didn't find a solution.

I've installed DVBDream, and first it seemed to work fine, but at irregular intervalls (a few seconds up to 50 minutes) the image freezes, while the sound still works properly. Sometimes it recovers after 10-20 seconds, somtimes the computer shuts down.
I've read that this might be due to video codecs.
I'm using the only codec I've installed: Cyberlink codec for both audio (v5.0.0.213) and video (v5.0.0.232) and no H.264 Codec (there is none)
I've read the Cyberlink codecs work fine with DVDDream.
I've tried all renderer (I've got 4: Video Mixing Renderer, Video Mixing Renderer 9, Generic Video Renderer, Overlay Video Renderer), but none works properly. With the Overlay Renderer DVBDream just shuts down.
Any suggestion what is wrong, or which other settings I can try (and how I can find them)?
Are there any free codecs that work with DVBDream?

I appreciate every help.
Thanks in advance.