Just a bit more info as I had another go this morning.
I tried to let the pc and DJM 2000 stay connected for over a minute once I'd started up the DJM in update mode and it went to it's white screen (as read somewhere that sometimes it takes 30secs-minute to assign an IP address ?), but sadly was no different.
It stiil just goes to it's white update screen and when I then started the Pioneer update tool on my Laptop, the screen is changing from "DJM-2000 Firmware Update version 1.28 please send the update file from your PC" to "trying to connect to your PC - 0% update" once I start running the updater on my laptop.
So I 'think' it must be connected to an extent with the LAN cable (as why would it know I'm trying to update from the laptop and change text on the white screen?) - but then it's still doing the same thing. Staying at 0% and not "connecting".
Hope somebody can give me some advice as really want to get all my gear talking to each other as rather stuck with this one ? :/