Okay, that sounds really strange - I have never had this happen to me even on a very sunny day.

I cannot find a way to this on a software basis, but couldn't you just block sunlight into the trackball by covering it with something?

A bit of a clumsy solution, and I do think that this sounds like a bug you should get checked out.

 

Yeh this is very weird. Mine is fine in sunlight and played with a few lamps there....nothing.

I agree with yenzehn, something is not right there.

 

just tried a bulb, led, uv and laser and nothing. not sure what to say

 

I was using mine yesterday in 29 degree heat (very hot for England!!) and it was fine... the trackpad is very sensitive but only to touch.

Sounds like yours might be faulty, I'd look into getting it swapped.

 

Put a piece of tape over it.

 

I've been getting this same problem as well, it happens to me about 3 times a week and it's very annoying, it scrolls right once every one or two seconds and I can't use the phone while it's happening.

 

Erm, the thing is, if your digitiser dies (the screen over the AMOLED screen that interprets the touch input), your phone will be useless until you replace it. How would you turn the trackpad back on? At least with the trackpad on, you could navigate the phone a little and use its basic functions.

 

Try a black dry wipe marker dabbed a few times in there. If you have any problems it can just be wiped away.

 

I had exactly the same problem on my Desire Z and I took your advice and so far so good. I used a black permanent marker and covered the trackball with a thin transparent tape. Thanks!