Update:
Well the service guy came out and said that there's not much he could do (surprise), that it's common to all Plasma and LCD (which I knew but others haven't looked as bad).
Anyway he accessed the service mode and changed one of the settings from AV to PC. This provided a small improvement to the way the pictures are displayed.
Best of all because he had to access the service menu no charge for me

I was surprised by how many settings there are in the service menu, not just text language but changing things like the power save mode (time and %), ISM timeout, overscan %, etc. Even down to settings for the display chipset, and the number of scart connections

Not so keen to go in and play with much though

.
In the mean time I've also fiddled with the DVD recorder and set it to progressive scan. This vastly improved the performance. This was mentioned in another thread for the RT-42PX10 (http://www.dtvforum.info/index.php?showtopic=6108&view=findpost&p=82818).
Only problem is the STB is still outputting interlaced scan signal (SD box). I can feed it into the DVD recorder via S-Video and then watch it from the DVD composite output in progressive and it's better than watching the STB from it's composite output.
Still interested to hear from others who have this panel...
cheers,
David.