It seems that while doing something for extended periods, like playing a puzzle game with no time limit, I notice that the screen is almost cycling through different brightnesses.

Now this isn't "lowering the brightness of the screen due to inactivity", I'm fully aware of that. This is happening while the screen is actively being used - it will suddenly switch to a slightly darker brightness - then a minute later, will spring back to full luminesence.

The "darker screen" is not as dark as a "power-saving mode" dark, but about halfway there. It's hard to describe. But it has happened repeatedly.

Might this be a power-saving function of the new firmware? Or sign of a bad screen, maybe?

It could be to do with changing light conditions and the phone trying to give you the optimal brightness for your screen.

Is the light sensor, probably you get with your hand sometimes over it while playing, so the device thinks its dark and lowers the display brightness (raises again when your hand goes away)...

As other have said, it's simply the light sensor being covered up, i found it very annoying. You can download the 'Simple Brightness Applet' that lets you change between brightness levels from any of your home screens.

CH

Oh, thank you so very much for that simple and logical explanation!

I was starting to get afraid the screen was going bad. I can live with it, as long as I know it's something normal - I ceratinly have beefy hands and I am certainly covering up the screen as I play (I use the stylus a lot and tend to hover over the screen as I contemplate a move).

Thanks again!