Thanks Jordan, I had uploaded the service data for the TX-26/32 LXD70 the other day.
Well hopefully good news, I've managed to find the firmware update which covers a number of chassis.
Version EU_HD_UK_LGSAM-v5640.SEC seems to be the cure, have to see how it works out.
I had a feeling by what it was doing it was related to the backlight tube(s)
Found it on avforums.com, a thread talking actually about this issue with the uneven mercury distribution in the tube over time making it hard to start.
I had almost given up looking, then found it

Will upload to the files section, I'm sure I'm not alone. Its still a great TV for my use. I use it mainly with a Humax 1100 Freesat box with HDMI.
Cheers for your help, it did motivate to keep looking :)