Right, quick update
Got the network completely wired and still no joy - so at least that shouldn't be a problem in future anyway.
Then I thought what the heck - and installed Debian Wheezy (64bit as suggested) and installed your deb and wouldn't you know it all works perfectly. You genius; many thanks for a great bit of work on the deb.
So now I know I can backup the old DVD collection using OGMRip as you suggested and can play everything without too much fuss over the wired network.
Think I may go back to Linux Mint Debian Edition but will try the 64bit version this time and then install your deb straight away to see that it works 'out of the box' as it were. Think Mint is just that much more user friendly when it comes to plain old 'day to day' stuff.
I'll post to confirm that your deb works on Mint 64bit as soon as I can
Many thanks for the great work and advice