Well I have had a fair bit of success in recoditioning the battery (technique at the bottom), though it wouldn't work on a totally wasted battery. Now it still does not want to start when it is cool without reset (which also is hard to get working when cool), but when it is warmed up there appears to be a lot less trouble. I think the heat has something to do with getting over the internal resistence in the battery (or circuit causing the trouble). Alltogether still not worth it, but if nothing else is wrong a battey replacement might do it.
Now this is not genuine recoditioning and I can't garrantee that it is not detremental for your system, but what I did was and what I think may have been happening:
Totally charge and deplete the battery a few times with backlight on low or off. Because of the resistance problems, high current draw due to high brightness levels will cause the unit too switch off early. After the battery life is increased do the same with a brighter level (full if it will take it) a couple of times. Now the battery has fukllest life at highest current. I have tried this on my GSM phone before but with very little success as the phone starts by looking for a network which uses high current draw meeting resistence and then switch off.
Can anybody verify this?
Thanks
Wayne.