our main tv decided to die not long ago, and me being like i am, opted for one of tescos cheap and cheerful 40" sets

does what it needs to do

however its got an auto standby which wont turn off, and its now starting to annoy me.

if anyone gets one of these sets and manages to get rid of the autostandby , please post
What do you mean by auto standby? Does it switch off if you haven't changed channel for a while?? There must be a setting in the menus for that!
it switches off after 5 hours if you dont use the remote on the tv ( which we dont). and yes you would have thought you could switch it off in the menus, but you cant. wot the nice folks at cheat tvs inc. have allowed is the option to choose between 3,4 or 5 hours before it gos to standby, it does tell you its going to standby 5 mins before hand and you need to press any button on the tv remote to stop it.

im hoping someone finds a service menu and it can be switch off from there
One workaround would be a universal, activity based remote control which you taught to include a TV remote Exit button press when doing a channel change and other significant events on the source box.
You could give these people a click/call - - my FIL has a Tesco Technik TV and I had to check if it would handle Region 1 DVDs - these are the people who support this brand apparently. There's a phone number on the site hopefully they might know how to turn the option off. I guess the other option is to see if the Hummy Remote can run the TV so at least when the warning comes up you can tap the volume button or something to keep it running. The manual for my FIL's TV did say there was more support available on the site/phone that isn't in the manual and they talk about help using Sky or Virgin so the same issue might arise for those users as well as you (or they might know which IR module is in their TV's so you can find it in the Hummy manual?)