Just thought, my other MD works with vdpau, and obviously that image was rebuilt.
The problem must be due to a combination of what I did to sort the NIC out, AND the rebuilding of the image.
Any pointers would be much appreciated.
Cheers,
Matt.
EDIT: Thoroughly confused. Deleted MD, started again, announces itself to router, kernel panic as expected, switched off, rebuilt image with "vdpau", and it freezes up at THIS stage. I haven't even done the r8168 module installation at this point.