I am using an HP IPAQ rw6828. I have quite a load of third party software on it.

I have been doing a full system backup and I find that after a time the screen backlight starts to turn very dim (but not off). I can only get the backlight on again by going to 'settings'->'back light' and move the slider back and forth. This problem comes up whatever power saving settings I have.

I can solve the problem by doing a hard reset and reloading the whole system from backup. After a week or so (usually if at any time the battery charge has dropped below 50%) the problem recurs.

Any clues what is going on?