Poor quality on kodicom 4400 card

[wheeliebin]

I have got a Kodicom 4400 card which is displaying very poor quality video in both ZM and xawtv. The image is in colour but heavily pixellated/blurred. I have a dying DVR which this setup is intended to replace and that displays the video perfectly.

What I need to decide is whether the fault lies with the card (second hand on ebay, maybe a clone?) in which case I'll get a new one or is it with my setup (in which case there's no point getting a new card...)

The reason that I am suspicious of the setup is that I get warnings from xawtv:
WARNING: No DGA support available for this display.
WARNING: couldn't find framebuffer base address, try manual configuration ("v4l-conf -a <addr>")

Surely if the framebuffer isn't being found somehow I wouldn't be getting any image?
I have read around this issue on this forum and others but can find no clues as to where the framebuffer is (in either logs or dmesg). in dmesg bttv reports that mmio is at 0xd8007000 which is the only thing that looks remotely like an address. "v4l-conf -a 0xd8007000" gives me a blue blank output in xawtv.

I have:
alias char-major-81 bttv
options bttv gbuffers=16 card=133,132,133,133 chroma_agc=1
in /etc/modprobe.d/bttv.conf

I'd be grateful for any input on solving this, and opinions on whether it is the card or the setup...