Heheh .. I don't speak german ... but XF86Config I do =))
I already saw your Howto ...

/ ... cyan screen .... nothing more to say ...
but .........
I updated nvtv to CVS version .. and WORKED !!! ;o) no more cyan screens ...
the closed driver from nvidia shows me a cyan screen but with nvtv I got a image .. and a nice one =) .. even if CVS version say unknow Philips 2:88 and pre-1 version say Philips SAA 7108 but didn't work ...
but .. in my TV out .. there's a line .. crossing my tv from top to botton darker that image ..

/ .. very annoying ... I will build my kernel with floppy support (I forgot last time) and post an image taken from a Mavica of my TV ;o)
Thanks for help ! .. ;o)